CYGNAR! Why? Well:

1. The average Cygnarian model doesn't make me go hey what the balls that dudes shoulder pads are just ridiculous (whats with wargames and massively oversized shoulder pads it's so lame).
2. More seriously the army has a more realistic feel to it the basic trooper (Trenchers and Longgunners) aren't that over the top fantasy wise their pretty realistic and have a very nice appeal to them when painted a line of gun toting long gunner looks fantastic on the board and Trenchers appeal to the WW1 nerd in me.
3. The fluff is awesome one nation standing alone against a world out for blood and their not without their own corruption (the Vinter regime being key) so they don't have the lame Puritan good guys crap going. They also know their alone and when you read their fluff they don't pin blame on anyone like that Ashlynn ***** whos got to stop whining about Lleal being Cygnars fault, though Cygnars pretty cocky as they've stood up against Cyrx, Khador, Trolls, Skorne the whole works they kinda have a good reason to be whos else has taken so much and has yet to stumble.
4. Stormknights...Stormguard, Stormblades, Stormlances anything of these look fantastic and they the cream of the crop in the Cygnar army and yet have a reasonable statline what they do have is the Electroleap and Stormblade with a standard bearer is hells loads of fun eight 3 inche AOEs everytime they charge is awesome.
5. Coleman Stryker...seriously a red head with a thunder sword who (in epic form) eats juggernauts for breakfast who can't love the guy.