If I remember correctly the 'handbook' and or BMW advises Castrol Edge 5w30 (although they now use she'll as their oil partner) but you should make sure it's the correct one for BMW engines. I was going to say LL-04 but I've a funny feeling that VAG spec from doing the oil several times on my sisters car.
I assume you have the service pack? So you can get a free top up. The warning is to advise you need a 1 litre top up so if your near a dealership just pop in.....would have to be tomorrow now unfortunately.