I owned a Suzuki GS500F. It's a 500cc "sport bike", more like a fared standard, because of the riding position (little more upright than a crotch rocket). It still goes when you twist the throttle, but if you make a mistake, you won't get thrown off (say as if you throttled a liter bike).

Since you have some experience I would even suggest maybe a used (couple years old) CBR, Ninja, or GSXR (600cc). Check your local craigslist.com listings, but make sure to have a local mechanic check it out. Definitely sit on some first and ride them if you can, find one with a comfortable riding position (I know the CBR is uncomfortable for me because when the steering bar is to the extreme left or right, my wrists hit the gas tank).

Unless you are looking for a cruiser?

Draconius can recommend some good rides, as far as me I would suggest a Honda Shadow, Suzuki Boulevard, or something similar. The Boulevard M50 (800cc) is a beautiful ride with an electronic ignition and a shaft drive.

Let me know what you're looking at and what you decide.

Save some money, buy used (sometimes dealers have good used motorcycles) - that way also, if you drop it, you didn't just drop your brand new bike

If you are anywhere near Western PA, check out westernpariders.com for some local rides!

Also check out this article: http://www.westernpariders.com/viewtopic.php?f=24&t=25