If you plan on using a SSD look for SATA3 plugs.
It's nice having rear USB3.0 and even nicer having a midboard USB3.0 header to plug in the front of the case.
I wanted something that would be compatible with the incoming Intel chips (22nm I think?).
I wanted a nice BIOS GUI and a "overclocking for dummies ez button".
I preferred a full size board for more room to get my stubby fingers.
I wanted a nice name brand (Gigabyte or ASUS).
Intel is the leader right now, AMD still a good choice if you want to pay a little less.
The Intel 2500K is an excellent choice that many seem to like. Great bang for the buck, bulletproof, good support, easy overclocking, nice onboard graphics.
Here's a great link for the differences in chipsets: http://www.pugetsystems.com/blog/2011/06/09/h67-p67-and-z68-which-one-is-right-for-you/
See sig for what I ended up with to meet the needs I listed.