What's a good antibiotic to take if your allergic to penicillin?

Cindamycin: An accepted alternative is clindamycin. The dose and frequency will need to be determined by your provider. Stay away from Amoxicillin or augmentin (amoxicillin and clavulanate). Azithromycin is also an acceptable alternative.

Depends: It would depend on the type of penicillin allergy you had and the type of infection you have. If you just had a rash from penicillin then cephalosporins like Keflex would be fine. If immediate hypersensitivity to penicillin, like hives or anaphylaxis you should avoid all penicillins, cephalosporins and probably all carbepems ( like imipenem). You can take all other antibiotics.