I don't know if I feel one way or the other about the first ED, but I think this first full OP is decent enough: http://www.youtube.com/watch?v=BBUhnx24Aak
The OVAs though if I remember right didn't have OPs and went straight into the OVA, and each also had different EDs.
But either way it's really the in-ep soundtrack that's the greatness.