Well it's gotten to that point where we really needed one for our crawling tot.
Our criteria was based on:-
-Recommendations from friends/family
-Ease of use and installation; not requiring it to be hardware fixed because we rent
With that in mind, we went with Safety 1st Perfect Fit Gate - $35 so the price was good considering how expensive some are, also it is a sturdy gate, not the best looking but it can be pressure fixed against the door frame.
Over all it works as a safety barrier, but as a opening gate, not so good because you do need to use the hardware for that to work, screwing it into the wall and using the mounts, which does take the point of the pressure fit away some what.
The auto fit system which seems good on paper, and when watching it work, does seem to work well, but it is only on one side of the gate so I can see how this might not work so well for people who have base board heat on both sides of a corridor or other things that could be in the way against the wall.
It is also quite heavy too, so definitely make sure you have it installed securely.
Over all, I think it works quite well and worth the money, though if we had our own house and could install a proper gate I would perhaps look at another option.