I've never have actually put thought into making a list, but since I just got back from my first trip to Kings Island a few hours ago, it made me put a little thought into it. So I guess it would look a little something like this:
1: The Beast (Kings Island)
2: Nitro (SFGAdv)
3: The New Texas Giant (SFOT)
4: Diamondback (Kings Island)
5: Tatsu (SFMM)
6: Outlaw Run (SDC)
7: Maverick (Cedar Point)
8: Raging Bull (SFGAm)
9: Millennium Force (Cedar Point)
10: GateKeeper (Cedar Point)
Looking at it... I don't really have a preference for any type of ride (though the B&M hyper coasters are my favorite type). I think it really depends on the mood that the ride ops put you in, as well as the excitement from the fellow riders. Those are probably the biggest two factors that actually come into play on my favorite ride experiences... which lead to my top coasters.
I seriously took my first night ride on the beast a few hours and I must say... OMFG It was the best coaster experience that I've ever had in my life!