I have a weird taste in my mouth. What antibiotics give a weird taste in the mouth?

Dysguesia. That's the technical term- "weird", "off", "metallic", other descriptors have been used. Most likely, the offending antibiotic is Flagyl (generic: metronidazole)- this is the leading reason for people to become non-compliant with this antibiotic. Other antibiotics have also this side effect (certain quinolones) but not to the degree seen with metronidazole.