I'm also in the market for a new one... I tried Cosmos, but two annoying bugs made me dump it - after a while, it would become impossible to click & drag spells/skills from one spot on the bar to another spot or another bar, and the +/- all quests button rarely worked. Sounds minor, but I found the two quite annoying... I've been using CTmod, but it's buggy as well - I often get error messages in the middle of my screen, prompting me to click "OK"... There's no discernable negative effect to these errors (gameplay continues unhindered), and there's nothing to click other than "OK", but they felt the need to inform me anyway :| My wants are pretty simple...
1) buff bar which displays my shaman's self-only weapon buff - the default UI doesn't, and there's no visible effect on your weapon if it's enchanted, so the only way to check if it's still up in default is to open inventory and mouse-over your weapon. It only lasts 5 minutes, so this gets annoying quick
2) easy way to determine groupmates' pets' health