I've been playing through the PC version for the first time using Glidos and it looks pretty nice and everything, especially if you enable the upgraded textures, but it feels a little off somehow since I'm so used to the saturated, aliased looked of PSX version. The PC version is also a lot easier since you can save anywhere. This is particularly useful on a few of the one-shot secrets. I remember the second secret in St. Francis Folly nearly breaking me on my first all-secrets run from having to do the whole first section over and over every time I missed that jump at the end of the slide. Surprisingly though it hasn't taken away the thrill of landing big jumps since I don't want to bother saving after every little thing. I don't mind the occasional backtracking.
The PC releases also have the advantage of the extra levels in the Gold editions, and though I've had the discs for years I've never gotten around to playing through them. What a treat, though, to be such a big fan of an older series and still have original levels to look forward to.
Accelerated graphics cards were the big new thing when Tomb Raider was first released. You could play the PC version either in normal mode and it would look grainy and pixelated, but if you had a 3Dfx/Voodoo card it would use anti-aliasing, mip-mapping and so on and look a lot smoother. You can play the normal version in DOSBox on modern systems now but it won't have the Glide features enabled. Glidos is just a prepackaged version of DOSBox that does everything for you and enables those features. It also adds the atmospheric music from the PSX version since those didn't play in the PC one and does a few other cool things. Costs ten bucks though.
All in all I'd still recommend the PSX version. The graphics fit the feel of the game better, it has the extra music, saves every level you complete, can be played with a controller without tons of workarounds and is just better put together.