San Andreas is the best!
I loved the wide range of transport modes jetpacks,bmx,boats,swimming,planes and ofcourse cars.The weapons could have been more though and I wished I could get the rocket laucher in ammunation shops.I felt that some of the missions especially those which required gun fights were not too flexible in how they could be tackled and mostly you are able to pass them when you knoe what to expect and where every bad guy is hiding.The girl friends besides the one in la sventuras and catalina play an insignificant role and I also feel the gang members taken by carl on some missions are more of nuisances and do not offer any assistance that's worth mentioning to the main character.
I loved the idea of introducing the skip trip function allowing me not to replay long journeys over and over again.