So im interested in the Tomb Raider games now, what games of the franchise do u think i should play and in what order? ( i'm PC only .. ) 
 
Thanks.

Underworld is quite new and it has that old TR feel to it.
Go check that out. The original one is also worth checking ofc, but there's this new version of it called anniversary I think.
Legend was quite good also.

Well, I've just recently finished up with Tomb Raider: Anniversary on PC.  It's a total makeover from the very original Tomb Raider from the PlayStation One days.  So maybe you oughta start there.  The only other Tomb Raider game I've played was Tomb Raider: Legend.  I can't really say much for the story aspect of these games, but I can say that the games can get very frustrating during the end-game especially when you come across puzzles that require you to do things quickly.  Other than that, the shooting and platforming can feel dated especially if you've played a similar game such as Uncharted.

Legend is a good one to start with. It's pretty easy compared to the rest of the franchise and gives a good taste of what Tomb Raider is all about. If you like what you see in Legend then play Underworld or Anniversary.