Now, I'm oldschool and sometimes it really shows. I always wrapped my tape by hand but alot of people are using the already-made kind and it's turning my thoughts. They can't undo and get all messy now!
Yoshida Champ grips are about a centimeter shorter than the others. They also come in varying thicknesses from 1 to 3 mm so you can adjust a bit for hand size and personal preference. The surface is a fairly sticky rubber that doesn't have much actual texture to it. And they come in lots of nice colors including some transparent ones.
Strong G grips come in corded and uncorded versions. The corded versions are a bit tougher and offer a bit more grip, but also don't stretch much so they fit standard alloy or steel bars fine but don't fit as well on anything else (Easton carbon track bars, etc.). The corded ones cost a bit more and there isn't really much point in getting them.
There are also some Soyo grips made with diamond-pattern texture that is extremely grippy with gloves but is a little too much for bare hands.
That's about it. There's more variety in bar tape than there is in grips.