Here is a picture of the Enterprises lined up together; the last one is the new version of the Enterprise from the post-2009 movies:
The first is the NX-class Enterprise from the Enterprise series; its crew complement appears to be 83.
The second is the original Constitution-class Enterprise from TOS; its crew complement is 205 in the 2250s, then 450 in the 2260s.
The third is the Constitution-class refit Enterprise from TOS movies as well as the identical rebuilt Enterprise after the original was destroyed. It looks like this version from the movies carried closer to the 450 complement.
The fourth is an Excelsior-class refit used in Generations.
The fifth is an Ambassador-class starship which appeared in the TNG episode "Yesterdays Enterprise".
The sixth, the Enterprise-D, is a Galaxy-class starship from the TNG TV series and also featured (and destroyed) in the movie Generations. Crew approximately 1014, plus 200 visiting, 15,000 total emergency rooming.
The seventh, the Enterprise-E, is a Sovereign-class from the TNG movies from First Contact onwards; crew approximately 750-850, 4000 total emergency rooming.
The eighth as I said is the new, larger re-imagined Constitution-class Enterprise from the JJ Abrams alternate universe "Star Trek" and "Into Darkness" (the increased size is due to encountering Nero's huge ship I believe).