I get SH4 gold edition ( u boat add on) it's cheep enough and will give you a much different feel.
Lots of interesting things happened in the PTO and with good mods
it will keep you interested.
TMO is my choice with and with out RSRD but RFB and FORTS are good as well. These are game play mods that change the way you play.
Check out this thread:
http://www.subsim.com/radioroom/forumdisplay.php?f=219
O! as someone mentioned you do get to "win the war".
Magic