First off, pointing out crap on the ground and the like (in my experience) is just part of the group ride roadie culture. I honestly think that it just more a matter of amusement then actual need to swerve.

Second, I will just agree with everyone that says there is no problem with 23s. I suppose I don't go over everything, but I do take the occasional curb. I guess you have to be a little more careful. But not really in terms of what is on the road. If it is going to flat a 23 it will probably do the same to a 25.

If you want the ultimate bomber tire go for the Vittoria Randonneur tire in a 28 (they don't come smaller).
They cost the same as the Rubinos but are double belted. They ride worse than the Rubinos but will outlast them by weeks and will never flat untless you run over a board full of nails.

I am not sure why it would matter. A tire is not going to make you faster. You want more tire to wear through on the back. Skidding and resisting wears your tire down. Also a 25 to a 23 is mostly taller then wider for road tires.

i've never really thought about running a fatter front tire on my skinny tire bikes.

i have some conti attack/force tires on my track bike and road bike. the rear is a 23 and the front is a 22. i don't really notice a big difference in terms of benefit or feel of the tire size difference.

on my geared hardtail, i run a 2.5 in the front and a 2.35 in the rear for the same reasoning as 128 mentioned.

i be runnin panaracer t-serv 25's. actually seem kinda big to me...but between them and a brooks B17 track angles can seem not so harsh sometimes... even on frickin girard ave.

It would prevented my last crash.

As for fatter tires go, I think 700x28 is a pretty good compromise. Good contact patch without being too terribly sluggish. 700x23 is scary to me in heavy rain, and in the dark you're bound to roll over some stuff you hadn't planned on rolling over.

I use 25c tires exclusively. The problem I keep running into is self-imposed: Less than 250g, and less than $30.
I currently have Conti Ultra 2000, Hutch Carbon Comp, Ritchey Tom Mix Pro, and Panaracer Stradius, all folding, all 25c (the Panaracers are marked 26c).
The 25's are usually marked with a slightly lower max PSI rating, 10-15 lbs, but as a matter of experience I find that I can run the back tire at 110-115 and the front at 105-110 no matter what the label says.
Actual Width: this, IMHO, is a running joke in the Tire Industry. About 15 years ago, before the 23c fad began, it was common for a tire marked '25c' to be 2-3mm undersize. The Conti tires are noticibly thinner than the Hutches when mounted on the same rim. Panaracers, and from my experience, all Japanese tires are thinner than they're marked.
Rim: the width of the rim matters. The same tire works very differently on different rims. My main fixed wheels are Campy Omega Strada XL (22mm) and my backups are Mavic Open Pro Ceramics (19mm). Big difference.
By the way I, too, am big: 5' 11", currently North Of Two-Hundred (yikes!). When I raced, I did so at 180-182 lbs. I used 25c clinchers and 24mm tubulars.

Bigger rubber means a larger contact patch, larger cross-section with the same rider and bike weight means less deformation of the casing, and therefore lower rolling resistance.
Back when I started the rule was to have tires at least 2mm wider than the actual rim width as a minimum, ie at least one millimeter wider than the rim on each side.

honestly, i use 23 and 25, and don't notice much difference. i sort of like the slightly more stable and comfy feel of 25, though 23s are a little smoother rolling...

it's not a big difference either way.

The Panaracer Stradius sport in 26 seems like a good choice. It's light weight, comes in 26, and is inexpensive. Anybody got anything bad to say about these tires? sabretech2001 how do you like yours? For the price if they are not junk, I think I will go with them.