As a side note, I was really disappointed that Rockstar omitted the ambulance and firefighter missions in GTA IV. The ambulance missions were one of my favorite parts of the pre-GTA4 games -- challenging and well-rewarded.
(Edit: ...and, as the article shows, these missions are some of the only pieces of the game that could be played entirely ethically -- which may be why they were removed. I'm surprised no one's created a similar driving-and-saving-lives sandbox game outside of GTA, although the taxi minigame is similar to Crazy Taxi, which may be where GTA got the idea in the first place.)
(Edit: ...and, as the article shows, these missions are some of the only pieces of the game that could be played entirely ethically -- which may be why they were removed. I'm surprised no one's created a similar driving-and-saving-lives sandbox game outside of GTA, although the taxi minigame is similar to Crazy Taxi, which may be where GTA got the idea in the first place.)