GS1150E Suzuki (even the 1100ES is an awesome sleeper)
Yamaha 700 Fazer
Yamaha FZR1000 (or any old 17"-wheel FZR)
Kawasaki ZL900 Eliminator (the 1000 was just fugly)
Any 17"-wheel air/oil Gixxer, slabby or slingshot
ZX9, ZX7
3rd-gen (1990-1993) VFR750
CBR600F2, or F2-tailed CBR600F3 (hated the later F3 tail, personally)
Hell, any late '80's to mid-'90's supersport, really - but (again), stay away from anything with odball wheel combos - gotta be 17" all around, or at least easily swappable to a 17" wheel from a newer bike (like the older CBR900RR). Anything carbureted and non-angular bodied supersport can be had for a song, and they all have their merits. If you don't mind heavier bikes that pose a challenge when searching for aftermarket parts, most '90's sportbikes are awesome values, offering performance and power that can actually surprise most riders - even the ones that owned the same bikes new back in the day.
Again - I ride dinosaurs 'cause I'm a classic bike fanatic and a tight ass, and I have a soft spot for certain bias-tired first-gen "modern" sportbikes - but for convenience, expense, and performance, STAY AWAY from any performance-type bike that won't accept modern rubber.
Now, if you're into standards or cruisers, there are a lot of awesome bikes out there with non-modern wheel sizes (like the Eliminator above - a ZX9 engine in a cruiser chassis), and a fair selection of sticky S/T-type bias tires. But if you're into draggin knee or hard parts, finding the right tire in a matching set can be tedious and time-consuming - and a hassle of making sure the shop hasn't had your tires on the rack for the past 5 years!
Gotta love this market as a buyer - but it sucks as a seller when it comes to non-bling or non-trendy bikes. Anyone wanna buy my Slingshot???
http://www.bayarearidersforum.com/forums/showthread.php?t=292516