Having been in Oxford for way too long (8 years...) I still don't think I know about even half the things going on here. It's an incredibly diverse place and there is a niche for almost everyone and everything, the difficulty lies in finding it.
The start of a new year is a good time to meet people, maybe by making new friends or joining another society that is more in tune with what you're looking for. Not all societies are full of hacks who won't talk of anything other than club politics.
I've probably had the most fun in clubs/societies where I learnt to do things I had never done before university, rather than in debating/political type societies. I think this is because while people had a common interest, they were more diverse in their opinions and backgrounds. If you meet people over an activitiy, you might find yourself chatting to them about philosophy in the middle of the night a few weeks later...
So personally, I'd recommend taking up a sport or activity that you haven't tried before (scuba diving? ballroom dancing? gliding? photography? ...) or continuing with another hobby you did in the past (sports? music? drama? arts? ...). Anyway, the start of the year is the best time, as there are so many people trying new things, just do something you enjoy, and chances are you'll meet more people you like along the way without even trying...