i just posted about the same topic the other day... i guess the best thing to tell you is to look at all the different ones and decide what is most important to you. some of the roms you may find are bloated with extra prgrams that i myself would never use, so i went with one that is farely clean and as close to stock as i could get with only minimal additions. right now i'm running ludester's rom. its all about what you want... and the only thing that will solve that is a look into the "vogue upgrades" forum and having a look around at all the great work these guys have put together.
edit: just wanted to let you know that i just built my own rom, and i have to say it is the best way of doing the upgrade. really simple and i got a ton of extra storage space to put my own programs. go here...
http://forum.ppcgeeks.com/showthread.php?t=26593 and take a look. just make sure you follow te directions to the "t."