Another vote for Ricoh!
I've had a GRD for a couple of years, and it's awesome. Even if it wasn't for the decent quality lens(decent might be an understatement) and teh fact you can shoot RAW, it's super easy to use and change settings on, you've got SLR-like controls with a pair of dials conveniently placed, and the buttons are mostly customisable, so whatever settings you want access to quickly, you can get to almost immediately.
Also has a proper hot shoe for external flash, or radio triggers even if that's your bag. Worth bearing in mind is you can sync a lot faster (up to 1/2000?) than you could with an SLR, due to it not having to shift mirrors around and that, which might be useful in some situations
That (and the newer GRD2) is a bit of a niche camera though, fixed wide angle at 28mm, with adapters to go wider to 21mm, or "tele" to 40mm equivalent.
The GX100 is 99% the same, but with a zoom lens, and a different pixel count. I convinced a friend to get one when she was after a new camera, and have a bit of a play with it. If I had the funds/less pressing priorities, I'd get one of them too.
Build quality on both is awesome, although the GRD would appear to win as it's got a magnesium body, and from personal experience, mine's taken a few good knocks and continues to work awesomely.