The whole series, mostly because all four games were in the current issue of our polish game magazine along with Rainbow 6 Las Vegas and Ford Off Road Racing.
Well, as for Hitman series, I can't say anything but that I love it. Next to Thief it's the best stealth games series ever created, Splinter Cell is nowhere near. The series got atmosphere, the story, great music and the variety of doing the missions. The worst fear that I have for the, most probably, upcoming Hitman game is going sandbox of semi-sandbox, like the new crappy Splinter Cell : Conviction game. The Hitman games have more of a non-linear sandbox games than most sanbox stuff I've played.
The best game? I'd say Hitman : Blood Money, the fourth one, and Hitman : Silent Assasin, the second one.
As for Rainbow 6 Las Vegas, after playing the true R6, the old, good, tactic one, I wanted to cry of what they've done for this game to sell it to the sheep. Yes, for money.
Can you say : baaah, you sheep that bought it? I uninstalled it after the mission inside the casino 1st level. Piece of crap.
As for Ford Off-Road Racing, well, it's a driving semi-simulation of an offroad licensed Ford cars. Budget game in my opinion, wich is suprising, because it tries to advertise Ford cars. I kept it on my disk because I don't have any racing games, besides piece of shiet that is Burnout Paradise on Xbox 360, and this game, even though a feature game is quite pleasing by not trying to be overly bombastic.