The Ballad of Gay Tony isn't just a piece of DLC for Grand Theft Auto IV, it's practically a new game in and of itself. Sure, the core GTA experience remains largely unchanged, and the sprawling Liberty City still serves as an expansive backdrop, but Gay Tony is simply a bigger and better game than The Lost and Damned (the first downloadable GTA4 "episode"). It's also quite a bit more entertaining and likable than its predecessor, which featured characters that most people would refer to as vile scumbags.
Excellent writing; tons of stuff to do after campaign; memorable, hilarious characters; parachuting is a blast.
Club activities get old fast; helicopter controls troublesome; if you don't like GTA4 you won't like this.