For normal battle scenarios, my favorites are the Clone Trooper and Magnaguard. Magnaguard tears up Heroes hardcore, Clone Trooper is just pretty much good at everything, especially once you get Elite Rifle upgrade. Favorite hero for these is Jango Fett without a doubt, imo he is much better than Boba because his shots are pretty much instant and have a longer range, Boba favors more mid range situations compared to Jango, and I'd rather have Han Solo in that case, or most Jedi.
My friends and I love to play the all-hero battle mode on Mos Eisley, two best heroes for that mode are Aayla Secura and Vader, for each team. Solo can only beat Jedi with proper support (usually from other Jedi), and the Fetts can't run away for very long. Aayla's force pull seems to have a much longer range than anyone else's, and her dash attack is much safer and covers more area than Heroes like Obi Wan/Mundi style chain attacks, and still deals more damage than Anakin/Emperor/Dooku style sweep attacks. Vader just deals ridiculous damage per hit, and has a good dash attack, so I abuse Choke->Dash attack for the most part.
Does anyone else like BF1 more than BF2? I feel like 1 has better maps (with the exception of Kamino), and Heroes just take away from the more indepth tactical aspects of BF1. BF2 Heroes can just run around the map putting out fires as they see them, in 1 you have to do things like trade bases in order to even something like that out.