This is a trick question. I think it's so odd to read here people praising TR3! 10 years ago I took for myself the challenge to beat all the classical TR games in order (from 1 to Chronicles, I don't consider AD a classical TR), and I kind of did (I didn't beat TR4).
My impression was that TR1 was an excellent game and TR2 was a great sequel, but I really didn't like the addition of so many humans foes, for me, they are simply annoying AF (foes in general in those old TR game are a pain and not fun to deal with, if there were a patch to delete the foes from the gameplay, I would install it). Othe think that I disliked about TR2 was the focus on non-temple like levels, but overall it was great.
TR3 is a mixed bag. It has interesting levels, but the game is sooo dark in many levels, so hard to distinguish what you're seeing. The impression that I have of TR3 right now, after 10 years of beating it, is that it was an average game with poor graphics decisions and a hard gameplay decision of making the save game crystals limited (at least on the PS1).
TR4... as I wrote, I didn't beat it, but I have a really nice memory of it. Great graphics, really nice gameplay, I loved the desition to base the game in Egypt, we're again deep down in temple/tomb like levels knee deep down. But the HUB system made me quit it! There is a point in the game that you reach a level that is a hub to 3-4 levels and you have to navigate through these levels in a different order and come back some a couple of times, it gets REALLY CONFUSING. You're totally used to just beat a level and move on to the next, and now you're faced with this HUB, where the gateways of the other levels are not that easy to find (you have first to realize that you're in a hub level!) and you have to keep track of the levels, what there is in each level (and they are themselves massive) , what keys/objects you're looking for, ... I got to confused that I quitted the game, it was even confusing to look up a walkthrough of this part. But that's the funny thing, I feel that probably TR4 is the best one of the franchise, but it made me quit...
TR5 is just an average game, I don't have very much to say about it.
I'm currently beating TR1 again, this time on the PC, and boy I'm really enjoying it. After it I'm considering if I go and beat the other TR in order or if I jump to TR4 and try to beat it using a walkthrough as guide when I get to the hub part...