I used to just settle for the cheap Stagg ones. You know how it is, money's tight and you can't afford to splash out. However, I actually snapped two of them, all the movement of playing kept the shaft moving and eventually snapped in the middle while I was playing! (Not live, luckily).
Now I have a
Tama 1st chair systems throne, fabric top. It's really worth spending the extra (in this case about £100 extra) for a totally stable throne. This one is silent too, I can hear my old ones on record creaking as I move. Not necessarily a bad thing, nothing wrong with lo-fi recording, but it shouldn't really happen. This
Tama is rigid, locks at the height you want and the double-braced legs look like they'll last a long time.