What case were you looking at?
I snagged a Thermalright Archon, which is very tall and very wide, but narrow, so it's not quite as whomg to install as a Silver Arrow or N-DH14.
If you want a smaller heatsink, and don't plan on going balls-out overclocking, the CoolerMaster Hyper212+ is a hard thing to argue with. It is not as honkin' enormous as the Silver Arrow by any stretch.
Most small heatpipe towers and aftermarket HSFs really aren't worth a shit, but if you want, I'd look around on XBitLabs or [H]ardOCP for reviews of coolers, they both have solid methodologies, and XBit has tested a ton of different coolers.
Edit: Archon sizing, for reference
http://i54.tinypic.com/24xey42.jpg
(Out of date pic is out of date... removed one HDD, added SDD, re-routed 24 pin ATX cable to avoid blocking airflow to GPU1)
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