The three part episode 'Tales From the Public Domain' (episode 14, season 13). Bart plays Hamlet in the section titled 'Do the Bard, Man'.
'Bart Wars' is not an episode of The Simpsons, it's a 112 minute DVD.
Bart's New Friend
O Brother, Where Bart Thou
Season 11|Episode 02|Brother's Little Helper
The New Kid on the Block, Season 4
'Bart Wars' is not an episode of The Simpsons, it's a 112 minute DVD.
Bart the Genius
Bart the General is fifth episode of The Simpsons.
Bart's New Friend
O Brother, Where Bart Thou
Bart has to see a pychiatrist in the episode Yokel Chords- after telling a scary ghost story in the school cafeteria to get free food
Bart of Darkness
'Marge Gamer' (17th episode, 18th season).
Bart the Fink, from season 7.
A bullfrog (assuming you're talking about the Simpsons episode)
The episode of the simpsons entitled "I Married Marge" in season 3.
Season 11|Episode 02|Brother's Little Helper