rotafix,
Take your pick
LGW, MAN, CWL, BHX, EMA, NCL, GLA, LTN, STN, BRS
All bases have their good and bad points.
LTN used to be great as you parked within spitting distance of the crew room front door. EMA is still like that.
At the larger bases it will be a while before you meet everyone. Bases like MAN and LGW tend to be pilot heavy and therefore we spend time helping out the smaller bases. I enjoy flying from the smaller bases because its usually less hastle and you're more likely to get away on time.