having owned or tested most of the m43 cameras, here's my favourites of the system limiting to 12mpx bodys only:
IQ: GH-1 (great DR, great BW files, a little weak jpg engine in colour but can be tweaked, raw files are great all over, swivel display, great grip and ergonomics, just enough external buttons, swivel screen makes it handy for legacy lenses too, decent hi-iso too for the sensor size raw is usable up to iso 1600)
colour: E-P3 (outstanding jpg engine, it's like shooting velvia up to iso 800. probably the best ever impremented jpg engine, not as sharp as the E-PL1 though)
sharpness: E-PL1 (budget body, lower low pass filter with near E-5 sharpness output, unfortunately plasticky body, with bad screen, and lacking external buttons)
allrounder: E-PL2 unlike the flimsy E-PL3 the E-PL2 feels like a real camera, also it has
the newer line of art filters, and good jpg output.
another great alLrounder is the already mentionned, GF-1, fantastic for the age, with great build and sharp files.
I sold all m43 I had keeping the GH-1 only, the files are very good, and to my eye the have something which comes close to M8 magic, also the 3:2 uncropped 12mpx feature is a big plus in my book, only the GH-1 and higher pixel count GH-2 offer this feature. video is still one of the best in class.
looks: the E-P2 in black looks great, unfortunately it lacks some of the great features of the E-P3
size: the E-PM1 hard to beat at that size and weight, for pure point and shoot few cameras excel it.
all that said, I have bad gas for a GH-3 but before buying I'd like to rent one to see what it will give me over the GH-1 in pure IQ, the ergonomics of the GH bodys are superb, the GH-3 is almosT identical to size to one of my favourite dslrs ever the Panasonic L1.
GH-1 (GH-2)
E-PL2/GF-1
E-P3
are my recommendations