ya want some that you can take on & off easily(try SKS) or ones that are mounted? (ie planet bike cascadia 29er's). Depending on tire size, the sks race blades are nice too.
There's probably more these days, but use a couple of different SKS blades & Xtra-dry's for the mountain bikes that are easy to take on & off, but a cascadia for the commuter/monster cross w/ fat slicks.
The Xtra-dry tends to sag down over the tire & loose some spray coverage in the rough stuff (most reviewers note this).