XCOM: Enemy Within takes the original game and adds new maps, resources, weapons, missions, enemies, and allies. I played a few hours on classic normal and it's basically Xcom:EU on steroids. I couldn't spot any glaring balance issues. Overall it's a good improvement that adds variety and depth that I thought was missing from the original, including the 2nd wave options that were patched in after launch.
Winner: XCOM: Enemy Within
Runner up: Battle Academy expansions, Panzer Corps: Allied Corps, Unity of Command: Black Turn
Battle Worlds: Kronos was the best overall indie tactics game this year for me, with some very strong contenders. It's based on the Battle Isle series of games, playing similar to Advance Wars and other WW2 style games.
Skulls of the Shogun is fun and fast paced, Just Tactics is a complex and involving PvP game, and Card Hunter is a cool D&D themed browser game.
The best tactics games this year are pretty much all on PC (with iOS/Android ports), and that isn't likely to change anytime soon. 2014 looks like a great year as well. Of course there are tons of indie tactics games on PC, too many to play and keep track of. Let me know if I missed anything good or great.
Winner: Battle Worlds: Kronos
Runner up: Skulls of the Shogun, Just Tactics, Card Hunter, Shadowrun Returns
There's way too many iOS and Android tactics games out there to keep track of and play. The three big ones this year are Panzer Corps, XCOM, and Frozen Synapse. If I missed some amazing iOS/Android game please let me know.
I'm giving the iOS/Android award to Panzer Corps for iPad this year. Xcom:EU is a strong contender but it's not the newest Enemy Within version. Frozen Synapse is apparently a flawless port and it's a great game if you like fast paced tactics PvP.
Winner: Panzer Corps for iPad
Runner Up: Xcom:EU for iOS, Frozen Synapse iOS, Frozen Synapse Android, Hero Academy Android, Great Big War Game Android
Winner: Skulls of the Shogun
Runner up: SRW Dark Prison, XCOM: Enemy Within, History: Legends of War
3DS was quite disappointing this year. Fire Emblem: Awakening and Project X Zone are both bad in terms of combat, balance, and level design, and loaded with fanservice to boot. I mean Fire Emblem: Heroes of Light and Shadow had such a great campaign, what happened?
The 3DS remake of Devil Survivor 2 with new content (subtitled Break Record) was delayed into 2014, which likely would've been my pick this year.
PSP/Vita's 2013 lineup is almost entirely imports, and it's similarly disappointing with mostly mediocre or forgettable games. Hopefully 2014 is better!
That's it this year, thanks for reading. Let me know if I didn't mention something you enjoyed.