[Bundlestars] SEGA Total War sale

They were featured in a couple of "Total War" bundles, as well as 2 "SEGA Strategy" bundles, on Humble Bundle, not too long ago:

• Shogun 1, Rome , Medieval 2, in $1 tiers;
• Medieval 1, Empire, Napoleon, Shogun 2, in BTA tiers (between $5 and $8);
• Rome II and some DLCs, Attila in high tiers ($15 both times).

They were all in tiered keys, so it's difficult to even find a trade for them.

If you want to try one, the veteran's response seems to indicate Medieval 2, Shogun 2, and Rome I/II as the best ones, so pick the one with your preferred historical setting... or wait for another bundle, if you're patient enough!

Which ones are best depends partly on your preferred historical setting.

Rome I and Medieval II are generally considered the best of the bunch (they're the same engine), though they're getting a bit older note that the Kingdoms expansion for Medieval II adds 4 complete scenarios that would each have been decent games in their own right
Shogun 2 generally considered the best of the newer games though, personally I find it the weakest; personal choice

Empire and Napoleon sit on a rung slightly lower; even though they're contemporaries of each other, they play and feel quite different. If you like the empire building / overland map, choose Empire, if you prefer the battles, Napoleon

Rome 2 and Attila are both alright, but probably the weakest of the bunch.

Shogun 1 and Medieval 1 are museum pieces. Can no longer be recommended to new players