It depends on what you mean by 'all round'.
100% pavement, then I'd say the FZ6. I like the sporty but comfy class for the road, 500-600CC. Light enough to be nimble, heavy enough for comfortable highway rides. (GS, Ninja650r, Ninja500, FZ6, FZ6r, etc). In that class, they all seem to be fine bikes, but the FZ6 just had the best feel to me.
Mostly pavement, some gravel/crappy pavement, then look at the Versys. I almost got one instead of my FZ. A good jack of all trades bike, but not as much of a smile generator as the FZ. If I didn't have a KLR650, I probably would have got the Versys (almost got it anyway, but found a great deal on a used FZ6). Not near as sporty as the FZ, but a good solid do-everything bike. It is a taller bike, but I think that's what helps in on the gravel/off-road department. I'd have no issues running the Versys off-road, but I'm not sure I'd want to run a long stretch of gravel on the FZ. Maybe if I find some knobbies that will fit the FZ

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Lots of gravel/crappy pavement, some off-road not too much highway, I'd look at the KLRs. I've heard the new models have a few issues so I'd do some more research on them, but my '95 has done good for me and is still chugging along fine. Good class of bike, I just hope Kawi didn't screw it up. A great all around adventure bike, but pretty lame on the highway but great on backroads. Kind of a poor man's BMW GS.