Does anybody have any idea why I'm getting such a strange wave on my waveform? It's an SE condenser, going into an m-audio preamp. Damaged mic perhaps?
Because I don't know how much time this took place over (what's the length of the sample we're looking at), it's hard to isolate what is causing the DC offset problem, but quite likely, you are using a half-balanced or unbalanced input signal that is tied to some ugly grounding. Low filtering will eliminate the problem if you don't need the low frequencies, but still, you are going to peak early due to this DC offset problem -- which will reduce your effective headroom.
Replacing a bad cable will likely resolve this problem. Use only balanced cables to get to your interface. If your interface uses 1/4" TRS inputs, use TRS to XLR cables.. NOT XLR to 1/4" guitar style connectors.