Natur ECB (/necb) does a nice job of showing some timers for targets like Divine Shield, Ice Block, and time remaining (counting DR) on stuns ... but it's displayed in a single reshuffled list, with the target name on the bar.
What I'd like is to show time-remaining bars on a few key immunities or CCs (something like buff filtering won't work on enemies; you need to parse the gains/casts messages), in a separate frame I can place near my unit frames, mainly for target and focus. I know Pitbull can filter auras, but that's not good enough for enemy buffs, and I want a more prominent "duration remaining".
For example,
WorldOfPapa.wmv - FileFront.com shows a mage with a custom "focus' divine shield timer" bar that pops up when his Paladin victim bubbles. Sucks to waste a counterspell on your focus when you didn't see the bubble ...