Small Unit Tactics game

You could try Brigade E5 or the Jagged Alliance series

The Last Remnant could be a good choice although its more rpg than strategy

Jagged Alliance 2, definitely
maybe the Commandos series?

The Jagged Alliance series is a good shout. Also DOW 2 and COH.

Another one to consider might be XCOM: Enemy Unknown.

XCOM: Enemy Unknown. Star Wars: Republic Commandos.

warhammer 40k, and maybe frozen synapse

X-COM, Silent Storm, Fallout Tactics, Shadowrun Returns, Gorky 17 (Odium).
A lot of tactical games on consoles, for example Operation Darkness, Front Mission or Valkyria Chronicles.

Bad Rats

If you like old school I'd recommend commandos and the front mission series. Front mission evolved is a modern day insult though, stay away from that.

The latest Xcom is great as well. The most recent two jagged alliance games are good, but don't really appeal to the diehard JA fans.

Worms Armageddon.

Frozen Synapse (?)

Refuse: Home, Sweep Home:
Refuse puts you in control of a squad of three toy soldiers, each with special techniques and unique weapons to help rid the house of plastic evil.

Desperados Wanted Dead or Alive, Commandos or Robin hood the legend of sherwood.

I've only played Desperados but they all have similar gameplay. Get your group of uniquely talented individuals and strategize your way to victory.

I'd suggest Small Soldiers and Gruntz. Those games bring nostalgia.

Shadow Watch, Shadow Company, Syndicate (the ancient one), Expeditions: Conquistador

Keep an eye out for Door Kickers which was recently Greenlit. I have been playing the alpha and it's great fun!

King's Bounty maybe?

Frontline Tactics. yes I know it's a F2P and everybody hates F2P but it's actually fun

frozen synapse

Cnc 4

Frozen Synapse!

X-Com: Enemy Unknown =)

Ground control

Running With Rifles is rather good, but I don't know if it's what you're looking for. You're one soldier in the middle of a war; if you try to be a hero, you'll get killed. You rank up throughout the battle, eventually being able to command a squad of your own.