k,bike novice, Rigid usually describes a bike with no suspension, good for unpaved path riding though some still like them for more aggresive trails. A hardtail has a front suspension that is best in a cross country aggresive to difficult plus situations. Full suspension is best where high speeds are involved on aggresive plus trails. 26" wheels are good for anything with the 29" wheels just as good and better on rutted, tree root infested trails. Full suspension and 29" wheels were developments primarily from the downhill racing folks.

I don't look at the different designs as one being superior to another, but what is best suited to for the rider and trail combo. All of the designs can comfortably overlap.

Brad