GTA:VC is better than fishing games, but not better than fishing.
no seriously though, the best fishing game ever is Sega Marine Fishing. the only reason i own a dreamcast. catch marlin, tarpon, sailfish, mako, hammerhead, skipjack, bluefin, dogtooth, and yellowfin tuna, bluefin and giant trevally, permit, stingrays, amberjack and more. in fact you could probably get a dreamcast, the game, and the fishing reel controller on ebay for the cost of 1 new PS2 game. its an easy game, but so enjoyable. also the arcade version (i go to broadway city arcade in manhattan 42nd st bet broad+8th)has a reel with a line attachjed to a counterweight system. tuna really pull down hard, tarpon jump yanking the reel, marlin run back and forth. its fun as ****.
the best old skool fishing game is The Blue Marlin for the 8bit nintendo (NES). troll for marlin, sails, sharks, cuda, tuna, mahi and other bluewater species by following birds, bait schools, or thermoclines. this is a tough game, but the most accurate.