Soldiers: Heroes of World War II was a real-time tactical game that came out a few years back. It's available on Gametap (requires 'Gold' membership, not free),
http://www.gametap.com/play/gameDetails/000352750. When it came out in 2004 its system requirements were a bear, but a recent gaming rig should run it very well.
Combat can move /very/ fast in some situations, but terrain and cover definitely matters. It isn't one of those RTSes where infantry can just shrug off an explosive tank shell or a burst from a machinegun nest. You need to be prepared to see your whole squad wiped out by an explosive shot or an accident if you aren't careful and lucky.
It has multiplayer, though I haven't tried it and multiplayer with gametap games is very iffy in general. Resource management is limited to keeping your soldiers alive, vehicles working (fueled and repaired), and weapons loaded. Additional weapons and vehicles can be 'acquired', but vehicles are usually disabled by time the enemy abandons them and you don't always have repair capability.
The time compression (and time slow) controls are important to know, sometimes there's downtime in a mission that you'll want to speed through and sometimes there's way too much going on and you got to slow it down to get your head around it. Slowing time during combat may help reduce the importance of reflexes, very vital, the UI (or the user) often can't keep up with the action.
There is destructible terrain and buildings with interiors, though you can't really look inside the buildings and thus use them for your own troops. But seeing as any building can be /driven through/ with tanks or turned into a smoking heap by explosives, this is perhaps just as well. It doesn't play as important a role since your soldiers don't get jetpacks, so flying to the top of a bunker and drilling into it is /not/ an option. 
The cover mechanic is pretty intuitive, the learning curve isn't bad but the difficulty is harsh due to the high lethality.
Vehicles play a strong role, they can be embarked/disembarked, soldiers can become crewmen and vice versa. A tank can easily suffer a mobility kill or have its turret knocked out, and infantry anti-tank weapons are very potent, so tanks don't dominate infantry as much as they do in most RTSes. Turrets do not traverse very quickly, so if you catch them up close without infantry cover, and you're quick enough, a simple hand grenade tossed under their treads can stop any tank and allow you to outmaneuver them completely.
A Panther or a King Tiger or an IS-2 is pretty god-like at long range, but even they need to watch out for panzerfausts, bazookas, and anti-tank grenades when infantry move up close, or anything that hits their treads. Damage effects depend upon the vehicle, explosive shells can actually be more lethal versus light armored vehicles than armor-piercing shells, and shot placement is /everything/. Vehicles that appear will depend on the mission, there's no base building at all it's all scenario-based, so you won't be able to bring a Firefly or an IS-2 to any mission and just steamroll them.
The number of forces you control depend on the mission and may occasionally approach 20 units but is more often a small squad. The demo actually gives a pretty good taste though it's one of the more challenging missions so just intensifies the learning cliff even more.
It lacks X-Com's world map gameplay, and it doesn't have Fallout's RPG mechanics, but as a pure real-time tactical game it does offer some unique gameplay. I think it graphically resembles Company of Heroes, but it's not as polished or easy to learn.
Another game, series actually, you may consider is UFO: Aftermath, UFO: Aftershock, and UFO: Afterlight. Each one is essentially that developer trying and not quite succeeding to capture the X-Com magic, but they're getting closer each time, closer at least to making a good game that's worthwhile to play. UFO: Afterlight is the most recent and most worthwhile, it moves the action to Mars and this change in formula allows them to focus in on the parts they're able to do best.
You will have to put up with bad voice acting, but visually they've gone for more of an art style instead of realism, easier on the eyes than previous entries in the series. It is essentially real-time but you (extensively) queue orders while paused. You don't get a big squad, I think your soldiers in one mission may max out at 6.
If Turn-based is okay, and you want a really solid tactical game with destroyable terrain galore, bullets penetrating walls and all that good stuff, I must recommend Silent Storm. Avoid the sequels and spinoffs, Sentinels is sadly very incomplete. Anyway, in the original Silent Storms you control a squad of six soldiers with class-based skill trees, and it's pretty damn nifty.
The introduction of Panzerkleins (mech suits) is pretty broken, they're immune to damn near anything the enemy throws at them and their lack of mobility makes them more boring than regular troops, but there are mods that remove them. Also, missions can take quite a lot of time to complete, so it may be exactly the kind of turn-based tactical game that you're trying to avoid.
[ March 30, 2008: Message edited by: Stromko ]
Author
Topic: Somewhere between tactics and strategy... (Read 3788 times)