Eran Rabani
I'm sure Rabani is a great guy. However, the same cannot be said regarding his lectures. He uses power-point slides, which are awful, and he's very boring. If you can take Chem 1A with someone other than Rabani (preferably Geissler), you'd be in good shape. It's an interesting course, however, it was made uninteresting for me because of Rabani