You need to work out your budget and needs and then get into a shop and handle them.
If you don't mind the bigger (than m4/3) lenses, Sony Nex looks good - especially the Nex7, which is expensive.
If you want to go smaller, the Panasonic G3 is a great camera. Smaller still, in the rangefinder-style cameras, it gets messy. The Olympus E-P3 looked the best on paper, but it's very expensive and I hated the menus. So I went for a GF2.
If buying again now, I'd have a good look at the GFx too.
There's also the Samsung NX system (larger sensor and lenses like the Nex), and the super-tiny Pentax Q and Nikon 1 series. Neither of the latter two appeal to me due to the loss of DoF control with such small sensors.