Rome Total War and Shogun 2 are the best.
Rome 2 was an utter disappointment at launch, but they improved the game immensely with patches... Attila is CA learning from Rome 2's mistakes and making a better game.
ARENA is different from the main series, but it's a BLAST to play. I've been in the Closed Alpha early this year and I can see this becoming a huge hit and a big money maker for SEGA.
That said, I feel like I'm getting fed up of CA not taking the Total War formula to the next level... They concentrate on improving the presentation with each entry but the gameplay has largely remained the same, if not worse than early Total War games.
Some of the improvements I would like to see in the TW formula:
- The ability to have control on how many men in a unit. I don't want to micro-manage 40 units of 160 men. I want to have the freedom to choose how many men I put in a single unit. If I want 4 units, with each having 600 men, I should be able to. You might say "You can group the units" but it would mess up the formations, and when one unit wavers and routes, they will break-off separately... Battles become (unrealistically) chaotic with your 40 units spread over the battle map, ones are routing, ones are pursuing the enemy, etc... In real-life, armies routed, not individual "units".
Next thing I want improved, is the formations. These played pivotal roles in real-life battles, but are not very useful in TW. For example, the Wedge formation... In real-life it was used break apart the enemy's formation, causing them to panic and flee. In TW it's just a numerical CHARGE BONUS. The enemies don't really get any penalties for having their lines broken. I feel the next step to improving the TW formula is to abandon these numerical bonuses and cool-down abilities in favor of an actual physics-based behaviors (Yes, I know they are also numerical under the hood). For example, a heavily-armored soldier should have his own mass and momentum to push a lightly-armored soldier back. This was kind of present in ROME 1 and Medieval 2 (Although it's unit based, not individual soldier based) but it's been gone from the series since then. Which brings me to my other point:
They need to do away with the 1v1 "dueling" animations in battles. It looks cool, but it doesn't work. It kinda worked in Shogun2 since it's Samurai warfare, but elsewhere it just looks silly. A dude surrounded by 6 enemies, and they just take turns attacking him instead of ganging up on him? This wasn't in ROME 1, but again, a result of their crappy Warscape engine. I also think engagements should be physics-based too. But I think it may be taxing on the computer's resources.
I could go on and on about the improvements I would like to see. There's just so much potential in the TW formula, but CA is not taking advantage of that potential, which is a shame. Probably because there is no competition on the market. There has been a few clones, but they were fairly obscure.
EDIT: Dang, I can't believe I wrote this wall of text!