Generally speaking,  the prices at restaurants (and hotels and virtually everything else) get higher as you move from the west end of the city  -  "Old Acapulco",   around & near Plaza Alvarez (a/k/a El  Zócalo) and on the Peninsula de las Playas  -  to the comparatively-newer eastern sections (the Golden/Hotel Zone,  Costa Azul,  & along the Carretera Escénica).

Many/most of the following restaurants  serve  -  and cook with  -  purified water and ice,  though it would be well-advised to avoid tap water and ice in smaller,  off-the-beaten-path,  local eateries (unless one has factual knowledge of the eatery's practices).   Try some of the  "classic (local) waters"  for a change  -  such as Agua de Jamaica,  made from flowers which give it a ruby-red color and a bit of a tang  ...  or Agua de Horchata,  made from rice with a bit of cinnamon and a touch of lime.   Avoid undercooked and/or raw foods  -  such as ceviche,  pulpo enamorado,  and sushi  -  if you have an especially sensitive stomach.

In no particular order,  the following restaurants and eateries are but a few of the scores of dining establishments found throughout the city  -  some of which rely heavily on the tourist trade,  and others which tend to attract local patrons (and a small number of tourists who've taken the time to seek them out).

>>>  UPSCALE/EXPENSIVE   -  typically located along the Carretera Escénica (or Scenic Highway  -  on the eastern/southeastern side of the bay) or in Zona Diamante (going over the hill,  eastward from the bay area,  toward Puerto Marqués and the airport)  -  many offering top-notch al fresco dining & surreal picture-perfect views of Acapulco Bay:

BAIKAL  -  on the Carretera Escénica 
BELLAVISTA  -  at the Hotel Las Brisas complex (on the Carretera Escénica);  al fresco dining;  fabulous views of the bay
CASA NOVA  -  on the Carretera Escénica;  Northern Italian cuisine;  al fresco dining;  great view;  elegant;  good service;  piano-bar 
KOOKABURRA  -  on the Carretera Escénica (in the Las Brisas area) with beautiful views of the bay 
MADEIRAS  -  on the Carretera Escénica;  stunning views of the bay;  newly-remodeled & re-opened (late 2007)                                                                                                                                                                                                                                           LA VELA  -  at the Hotel Camino Real (Zona Diamante) overlooking Puerto Marqués Bay;  specializing in seafood                                                                                                                                                                                                                                      EL OLVIDO  -  Exception:  at mid-bay,  in the Plaza Marbella at the Diana traffic-circle;  bayside/beach-level;  elegant
COYUCA  22  -  Exception:  on the Peninsula de las Playas;  beautiful views of the bay,  especially at night;  white-glove service;  elegant

>>>  UPPER MID-RANGE  -  generally located along/near the eastern half of La Costera Miguel Aléman,  the city's main boulevard:

LA MANSION  -  on La Costera,  at the Veléro y Galéon Condominios (across from the Acapulco Golf Course);  a well-regarded steakhouse in the Golden Zone                                                                                                                                                                                                                                                                                                                                                                                                              EL GAUCHO  -  on La Costera,  at the Hotel El Presidente;  an Argentinian steakhouse                                                                                                                                                                                                                                                                                                                                                                                                                                                              TERRA LUNA  -  on La Costera in Costa Azul,  across from HardRock Cafe;  pastas,  seafood,  & specialty crepes;  small/quaint;  indoor(air-conditioned) & outdoor dining;  signature dish > Coconut Shrimp                                                                                                          SUNTORY  -  on La Costera in the (eastern) Costa Azul section;  upscale Japanese cuisine                                                                                 EL PESCADOR  -  at the Hotel Hyatt (across from WalMart,  eastern end of La Costera);  specializing in seafood dinners

>>>  MODERATE MID-RANGE  -  various locations throughout the city,  though most are along La Costera  -  east of mid-bay,  in/near the tourist zone:

BETO's  -  on Playa Condesa (at the bungy-tower);  overlooking the bay;  long-established & specializing in seafood                                                                                                                                                                                                                         PARADISE  -  on Playa Condesa (at the bungy-tower);  overlooking the bay;  long-established & specializing in seafood                                                                                                                                                                                                                              FORZA ITALIA  -  on La Costera,  near the OfficeMax store;  affordable Italian cuisine;  indoor/outdoor dining;  very popular with tourists                                                                                                                                                                                                                              O'JARDIM  -  off the beaten path (inland / northwest of mid-bay),  yet worthy of a visit;  chef-owned all-you-can-eat Brazilian-style  "meat lovers'"  restaurant;  about U.S.$22/pp (as of early 2008);  very unique                                                                                                           SIROCCO  -  west of mid-bay;  Spanish cuisine (not Mexican),  known for their assortment of  "paella"  entrees;  romantic bayside/beachfront setting                                                                                                                                                                                    ZAPATA, VILLA, Y COMPANIA  -  at the Hotel Hyatt(across from WalMart,  eastern end of La Costera);  traditional Mexican cuisine                                                                                                                                                                                                                                     LOS FLAMINGOS  -  at the hotel of the same name,  on the west side of the Peninsula de las Playas;  long-established & very well-known;  mostly Mexican fare (and traditional Thursday-only  "pozole");  a cliffside setting overlooking the Pacific Ocean makes this a perfect spot to enjoy an Acapulco sunset                                                                                                                                                                            LA TORTUGA  -  just off La Costera,  near the TelMex building in the Golden Zone;  Mexican cuisine;  in the process of moving to a new location (just nextdoor) - spring/2008;  no credit- or ATM cards accepted

>>>  LESS EXPENSIVE   -  many are centrally-located along (or just off) La Costera,  from one end to the other;  some could be a challenge to find & might require a bit of research and/or inquiry;  the majority offer either traditional made-from-scratch Mexican fare or specialize in local seafood dishes 

EL AMIGO MIGUEL  -  original location near el zócalo (the town square in Acapulco Tradicional);  second location at Playa Hornos;  Mexican & fresh seafood 
EL CABRITO  -  on La Costera (across from HardRock Cafe);  Mexican cuisine (specialty of the house > "cabrito" / kid goat);  a varied & affordable menu;  indoor & outdoor dining (no air-conditioning)
LA CASA DE TERE  -  inland,  off La Costera,  on Calle Alonso Martin (generally up inback of the Galerias Diana shopping mall at mid-bay);  traditional Mexican menu - very affordable;  pozole specials & a Mexican trio on Thursdays;  closed Mondays
EL FOGON  -  two locations (one at the mid-bay Diana traffic circle,  the other on La Costera in Costa Azul);  Mexican fare;  good lunch spot
LA MANSION BOHEMIA DE LILIA MARINO  -  on the Peninsula de las Playas (near the B&B Disco;  only open on Thursdays,  from afternoon on,  for the weekly pozole festivities;  extensive menu;  live on-stage music & singing
MARISCOS PIPO's  -  two locations (the original - just west of el zócalo in Acapulco Tradicional,  the other on La Costera - just west of El Cabrito & HardRock Cafe);  fresh seafood entrees
SANBORN's  -  several locations along La Costera;  classic Mexican cuisine;  bargain lunch specials;  comparable to U.S. Denny's restaurants                                                                                                                                                                                                                                EL JAGUAR  -  on La Costera,  near the Hotels Calinda & Malibu;  specializing in Guerrenese regional & coastal (Mexican) cuisine                                                                                                                                                                                                                                         MI PIACCI  -  at el zócalo (the town square - Acapulco Tradicional);  Italian fare;  indoor & outdoor dining

>>>  ECONOMICAL

LA CABANA DE PEDRO  -  Peninsula de las Playas (on the road to the bull-ring,  on the righthand side - just after turning off La Costera near the Farmacia de Ahorro & before the VW and Honda dealers