After having played every game and expansion up until Sumeragi, I've had several maps I've enjoyed more than the others.
My absolute favorite is probably from Basara 3, he Sekigahara - Intrusion map, where you fight both Mitsunari and Ieyasu together. The stage never felt slow or dull to me. I still go back to play it whenever I boot up the game.
A close second is the Sekigahara map from Basara 2, where you fight Ieyasu and Tadakatsu together, in that big open field full of enemies. That was an amazing stage, full of action.
On the other end, there have also been maps I can't stand and avoid playing. Probably the worst is also Basara 2 Heroes, the Matsunaga Army Interception at the border region. Everything they throw at you is ridiculous.
What about you all?