2 that I think look and perform really good are cynogen with drotheme and Pete's 1.0 with the nextheme theme skin. Some slight differences. Jrummys themes are nice too since it similar to nextheme but in different colored variations like blue, cyan, red, green and I think there is one more but I can't remember. What I would say is try a few out and just create a backup of your current one through rom manager since it will also back up your settings so you wont have to start from scratch if you want to revert back.