I've played hitman absolution, as well as all the other hitmans, with the exception of agent 47. I thought absoloution was amazing, some great features in it and it's a great single player game, multiplayer is poor but what can you expect from a game like hitman? contracts is a nice feature, not spent much time on it. Overall i think hitman would be a good buy if you have played previous hitman games and liked them.
Since i haven't played borderlands, i'd probably buy that.