Please help with game choice.

Company of heroes is a great game. just check the reviews.

Supreme Commander and teberium wars are probably better than the other ones youve listed

Total war all the fucking way, it will end your life. You will be so in to the game if you loose the main campaign you will end up throwing your self on a claymore in discuss at your own failings as a ruler to your empire. Oh Medieval 2 Total War will be a much better choice if you have a system to cope with it. Currently playing through a game as the good old Scots, I am invading France and the Spanish boarders… that’s after I crushed the English empire and severing the kings head from his body but not before killing all his children…

FREEDOM!!!

Really though if you want a good game, and a good game that lasts just get total war and stick it on the hardest skill setting. It will take you months to complete on a normal campaign game if you are a casual gamer and once you complete the game you will get such a feeling of accomplishment that any man would not fault you if you ended up jizzing in your pants.

I've been playing Supreme Commander, it's decent, I already preordered Tiberium Wars, C&C fanboy I am (except for generals and RA2, never like em that much).

I haven't bought an RTS since Warcraft 3, and I never like it that much, starcraft all the way!

I would go for Warhammer 40k. While the AI is better in CoH I really like the style and feel of warhammer. Sort of like playing starcraft (isn't starcraft a ripoff of the warhammer universe? ) with better gameplay and in 3D.

Of course you couldn't go wrong with any of your choices.
AoE is a more traditional RTS when it comes to gameplay
COh and Warhammer are RTS titles with a unique resource system (really improves on traditional RTS resource gathering) where CoH is WW2 and Warhammer is starcraft like.
Rome is a mixture of TBS and RTS (the baattles are RTS fighting only building and everything else is TBS)

There all great games, try and get Compay of Heros Special Edition; as you get Warhammer 40K for free! cheep here> http://www.game.co.uk

If you're going to get Dawn of War then I'd reccomend getting both the expansion packs too. They seem to add a lot to the game, especially the last expansion pack.

I've played Age of Empires III and thought it was really bad, I wouldn't reccomend it at all.

Company of Heroes is good, it's made by the same people who made Dawn of War and is similar. The major difference is that Dawn of War is sci fi and Company of Heroes is WWII.

I haven't played Rome: Total War but I've heard good things about it.

I agree with the post above best to get dawn of war with the expansions (even though I feel the Necrons are tooo powerful)