I guess it depends on what the REAL, day-to-day use of the object is going to be, and if you ever plan to move it.
It sounds like it's built-in-place, so you have more options relative to weight.
I haven't lived with the synthetic stone or quartz, so I really don't know how it would be.
Real stone - either slab or tile - is timeless and wonderful. However, I have learned that it is not quite as "maintenance free" as people might like you to think. A big slab of granite would be lovely, but I don't think you can probably DIY.
If you don't abhor the look of grout lines, ceramic tile offers the optimum for creativity and easy maintenance. I found that using dirt-colored (black, in my case) epoxy grout from Laticrete basically eliminates any concern about maintenance of the grout lines.
EDIT: totally forgot...
Wood is lovely, but nobody's found a sure-fire way to keep it lovely in the last 500 years and you're not going to be the first. If you like the way it looks and are amenable to it developing some character as it gets used, good on you.
I saw a few examples of concrete countertops that I liked.
Time and money, buddy.
Have fun. Need pics.
Last edited by tomtuttle; 02/21/12 05:05 PM. Reason: D'oh.