Although a reader of my previous post had some success with CrossOver Games and its handling of the old Tomb Raider III demo, it appears that it has some way to go yet before it can be taken seriously. The Unofficial Apple Weblog (TUAW) has published a review of CrossOver Games, and although they had some success, it was limited and somewhat buggy. So be sure to check the CrossOver Games Game Compatibility page for the games you want to run, and take some time with the demo version to satisfy yourself that it is right for you! (At the time of writing, Tomb Raider II is now on the compatibility list - as the PC TRII is a lot easier to find in stores than the Mac game, then I suppose that's a good sign ;-)
However, as CrossOver Games is a new product I expect that it will see considerable improvement in the months to come, but I doubt it will ever rival Boot Camp. It's the old story - you gets what you pays for! Best is to wait for a Mac version of your favourite game (on the off-chance it might appear...); next is to play the Windows version in whatever way you find works for you; or do what I did and move to the far cheaper high definition consoles.
For the absolute game fanatic who demands the best a Mac isn't an option anyway, and for everyone else an Xbox 360 and/or a PlayStation 3 will give a very satisfying experience at a budget price, only rivalled by a carefully specced Mac Pro at a much higher cost, or a custom built PC for maybe a little less than the Mac Pro. I may be biased here as I have a long familiarity with console gaming, but the modern Tomb Raiders (since Legend) are perfectly suited to the PlayStation controller, and only slightly less suited to the X360 controller (I found the 360 left stick/D-pad a little awkward at first, but that could be due to my 8 years or so with PlayStation). The traditional TR keyboard controls are nice but less relevant with the far more complex modern games which demand the mouse as part of the controls - a good gamepad would probably be a better option these days with Mac gaming.