it depneds
night fire- if u like the bond films its not only fps u get to drive veichles as well
time splitters 2- if u liked the first one you should get it, a good traditional fps and a bit sci-fi in it aswell and a great multiplayer!!!!
those are my reasons for each game to be a buy, also if the choice was down to me i would choose night fire!
best get more opinions first though!