[adrians69]

It all depends on which theatre of operations you are interested in. If you want Pacific ops then SH4 is your baby. It's a bit more difficult if you want to do U-Boats though. If you want the best SH experience around but can put up with the slightly dated graphics, then SH3 is without a doubt the best one, however if you want a more up to date version, SH5 is the way to go but ONLY with a good mod set (e.g. The Wolves of Steel mega mod is a very accomplished modpack).