First, let me ask you-- where abouts are you? This makes a big difference in what materials can be safely used.

Concrete counters.

WE have a couple of used slabs of some kind of composite from a University science lab that we have carted around the country from house to house. Not sure what they're made of, but we have used them as outdoor counters for about 25 years and 5 houses!!!

They had a black finish on them, and we spray painted them a glossy black. Super easy to hose and scrub down- no grout lines, etc.

Concrete can be finished off to look like anything, even large tiles, and can be done in any colour.

I have a stained glass tile set into my concrete pavers walkway, and JUST this year (11 years later) the glass started popping off, but that it is on a well-used front walkway, in a counter, could look fabulous (as accents)

Northern Virginia

I am worried about cracks from freezing and thawing with concrete. Is that concern unfounded?

It depends if it's poured in place or precast. Precast, there's not much to worry about. you also might think about using granite slab. Not necessarily polished, either. For something outside, I might even think about flame honed.

My girlfriend has a gorgeous cooking/eating island with a granite slab counter (I think it's polished but not sure), and it's held up wonderfully over the last eight years or so. We're in southern California, but Bill seems to think that would work in your area.

I'd go with granite. I have travertine tiles on my outdoor counters and the grout is a stain magnet. Someday I'll rip it out and replace with granite slab.

I think soapstone would be good. When we get ready I have some plans floating around in my head concerning soapstone as counter for grill etc.
Bill - soapstone outside in zone 7 - MD as well as VA?

Soapstone is definitely a contender for an outdoors countertop. Check out this outdoor kitchen in the link below from Green Mountain Soapstone.

Here is a link that might be useful: Outdoor Kitchen with Soapstone Countertop

thanks for the link marthavila. Does look nice doesn't it?

My other thought was Slate, although that would have to be tiles I guess, I can't imagine getting slabs of slate that big and it be stable. Anyone know if that IS a posssibility?