I have used many many ROMs for my TP2 and I have settled on
AthineOS 6.5.5 23xxx build. It has the most features and is very quick and customizable.
b16b (the ROM cook) provides a CHome only version (CHome is the WM default UI), or Sense 2.5 version. He also provides 6.5 21xxx builds. I use CHome Only 23xxx build and
iPhoneToday 1.5.1 for my program launcher/UI. Sense is too slow for me and it doesn't do what I need it to.
All that said, it's also very dependent on your personal taste.