Hmm.. I guess it's partly a matter of what you need it for. For what it's worth, I opted for a PMDX breakout board and I'm very pleased. This particular model was a bit less expensice than others, and included an on board built in relay for spindle control. More info is here http://www.pmdx.com/PMDX-121/index.html
I only use it for a simple 3 axis machine. I use mach2 so I thought the charge pump feature that stops the machine/steppers when the software froze or had a problem was a good feature. If you need more replays to control other stuff, or more specific features, you may want to look at their other model or try another brand board. I haven't tried others so can't offer any advise there, but this one worked for me as discribed in the manual and ordering was straightforward and shipping was fast so no complaints.