I feel that 700 is the smoothest rolling wheel over rough pavement, but 26" wheels have an advantage of being inherited stronger if you are a heavier rider.

One bike, 26" wheels. Reason #1 for the ride: the ride. Commuting just accomplishes another purpose.

Since the tire size contributes a little to this whole thing, I'll list that as well:

700x28, 700x30, 26"x1-3/8" (650A), 26"x1.75"

I've had good commutes on all of them, but the larger tire sizes let me relax a little more when going over rough pavement.

406 and 559. One wheel of each size. Works for me.

I don't get it...

700ccx32, 80psi

The differences in tires (between say 700x25mm and 700x35mm) are going to be much bigger effect on rolling over rough pavement than different wheel sizes (say, 700x35mm and 26"x35mm).

Do you ever mix it up and go with a 559 front wheel and 406 rear?

Then he'd feel like he's going uphill all the time. Who wants that?

I commute on both 26'' 1.5 and 700 x 23c. The 26'' is more comfortable on damaged roads but is/feels significantly slower than the 700c. I have to work harder to keep speed on the 26''.

I've got no problem with this statement as long as people realize it's got nothing to do with wheel size (tire size/composition/pressure, yes, wheel size, no).

Could even be the bearings used in the hubs on the 26" wheels don't spin as well as the 700c wheels. Try turning both bikes upside down, spin both front wheels, one with each arm, using approximately the same force, and see which one spins longer.

28" (40-635) but probably only because that is what my bicycle has on it and I love that bike. If I had another I would probably go with something comfortable in the 700c range just because finding tubes and tires is far easier at a moments notice.

26"/1.4", and 700/25. I don't know which I "prefer" yet. One is rough and ready and the other is a thoroughbred. Both get me to work feeling great about the ride. I suppose that the 26" wheeled bike is more of the "just jump on and go" which can be a very good thing sometimes. I run a 1.4" Michelin slick on the 26" bike...

Favorite wheel size? The right wheel for the job is my favorite. Sometimes it's these.

I bought a new bike with 29" rims and it cuts about 5-10 minutes off my commute (I like my commute, so this is not always a good thing). My old bike had 26" rims.

Ugh.

It's not the wheel size. It might be your position, the gearing, the tires. But it's not the wheel size.

No, because then I would lose the inherent passive coasting effect of a small front/large rear bike.

Ahhh. Ok. That makes sense.