its true fighting games have little replay value, especially the story mode is crap and only reason to finish all characters is to use seth.
but if you are good at sf and would like to play lots of games online vs other ppl then there is a lot of replay value. the lag is fricking so good with sf iv thats its just not funny.
trial mode, survival mode and time attack mode for me is zzz... i jus wanna beat the **** out of the opponent online.
so id go for skate if i was u, if you were a die hard fighting game gamer that loves the mind games/combos etc then you wouldnt have asked the question in the first place.
so... go for skate.