Woah, nelly...can you ever! You can snipe anyone no matter what vehicle they are in (even a helicopter), as well as shoot out tires (or have your tires shot out). You can do some insane jumps on the motorcycles, and you can also buy property around Vice City. I've already managed to complete all of the assassination contracts, attempt 100 missions, buy 6 properties (including a strip club and Kaufman Taxi, which help provide a regular income for you), own 2 helicopters, kill over 400 people, achieve a "Stuff of Legends" notorioty rating by having the National Guard called out on me over 5 times, established more steady income by threating business owners to pay "protection" money, helped a Brit punk band avoid a homicidal stalker, joined a biker gang, helped a Cuban gang thwart the Haitian drug runners in a territory war, robbed the bank holding the SWAT team's finances, took control of a weapons smuggling operation, as well as an ice cream business that is a front for another drug smuggling operation.
Even after all of that, the game stats say that I'm only at 40% complete.
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If it wasn't for bad luck I wouldn't have no luck at all. D'OH!