I've just bought the lindam numi which looks really good though it does affix to the wall (and is pretty pricey)....
http://www.amazon.co.uk/Lindam-Premium- ... 60&sr=8-37
Previously I wanted a pressure one as I didn't want to fix to the wall but actually this one is so much better, safer and sturdier.....and it doesn't have a bar at the bottom so you've got nothing to trip over. If your concern is about holes in your walls, it's pretty easy to get a decorator to fill a hole and decorate so not a problem once you've finished with it.
The pressure one I had was from mothercare, again it looked so much nicer than the normal ones - they've changed the style now and I don't think it's quite as nice as the old one, but it worked quite well and looked nice (though again you can definitely get cheaper). It was so difficult to open for kids that most adults couldn't work it out either!
http://www.mothercare.com/Easy-Close-De ... 1331030028