Anything from Vice City for me as well. I found the radio in GTAIV as bland as the rest of the game - going for "realism" was not a good move on Rockstar's part. It did, however, FINALLY provide me with a context where Ruszlana's "Wild Dances" actually worked - killing two bodyguards and then jumping into a real shitty car to chase down and finish the local russian lowlife boss with that song coming out of the radio just felt so right. Good timing, I guess.
"Is like Fernando say to his ex-wife: 'I love you, please, don't leave me. It is not what you think - I was bitten by a snake and the nice lady, she came to suck out the poison.' This story, she no work very well."