Well, I hate iTunes. I
really hate it. As a programmer, I hate it even more.... overbloated with features, memory hungry, slow, sometimes eats 100% of your CPU while you're doing something else...
IMHO a very good replacement is
Anapod Explorer... I've been using it for almost one year without problems. Unfortunately it's not free, but if you try it I think you'll never want to switch back to iTunes!

I've never tested its OGG->MP3 conversion capabilities, but they have a free trial version if you want to test them for yourself. Oh, and it even lets you copy music FROM your iPod to your pc!
I hope you'll like it!