I've never used OpenOffice for OS X, but I've used the StarOffice 6.0 beta (which is based off of OpenOffice) for Linux. I liked it. It never crashed on me in about 50 total hours of usage, I didn't notice any shocking bugs, and it was free. OpenOffice for OS X, though, runs only under XDarwin (the OS X X11 server), as far as I know, which means that it looks ugly (a gray appearance rather than an Aqua appearance). It's pretty full-featured, though. It did everything I needed it to do. Which is not very much, but...
I use AppleWorks as my "office suite." (Actually I only use the word processor part of it.) It's alright. It has some problems, like not-completely-Aqua word processing windows, no mouse scroll wheel support, windows sometimes stretch off the bottom of the screen when you open them making them difficult to resize, somewhat ugly Carbon fonts, buggy lists, and an interface that is a bit strange at first. It has only crashed on me in OS 9, though - never in OS X (and I've used it 100x more in OS X). It is also quite lightweight. I would recommend it. I may be mistaken but I think it's $30 if you can get the educational discount.
Alex