I use Safeguard traps, which are the same basic havahart design but better engineered. The only downside is that the trip plate is too thin (a cat could step over it), but this can be fixed by taping a 6' piece of stiff cardboard to the plate, making a longer ramp.
http://www.neighborhoodcats.org/info/recommendtrap.htm
However, I purchased five new traps in May and was sorely disappointed in the quality. Two of the backdoor clips have already broken,
Yes, this happened quickly with my Tomahawk too. I don't really like the eyehole+latch design on the second door either: the latch gets in the way when transfering cats.
one trap was so bent in shipping the frontdoor wouldn't open
Interesting. This is exactly what happened to me too. I sent it back and they promptly shipped a good one.
Next time, I'm ordering the large Tru-Catch traps.
They are heavy! And setting the trigger is a bit of an art form. But otherwise they're very good too.
One really has to go with 36' models, so-called 'raccoon traps'. Some of the traps out there being marketed as 'cat traps' are just too small.