In order, my most to least favorite murder maps are Lunar, Clue, Italy, Office, Lock Up, Temple, Dino Mines, Overgrown Lab, Grave Gardens, Mansion, Tom's Funland, Haunted House, and Electricity. Electricity is the only map I'd literally refuse to play on, I just leave if they chose it.
I love open and fun looking maps that have rooms and twists and turns that I can memorize, and while Lunar, Clue, Italy and Office sort of look like copies of each other, they're really fun to play on and feel familiar.
Mansion annoys me because of the tall grass and camping spots, I can't remember where to go for the vents half the time on Overgrown Lab, Temple has too many camping spots as well, and Electricity makes me think that I'm high.