Can vouch for the Thudbuster. I use it on the Tandem and "Who needs full suspension?"

It is pricey but it works. Even on the biggest of hits offroad.

But if I had a choice of good front suspension or a thudbuster -I would put the money into the forks. You can always lift your butt off the saddle on a hardtail (Unless it is a tandem and you don't get any warning)