Okay... I've found a lot of things I see problems with. I'm trying to offer constructive critisism here; I'm not just badmouthing your site or anyhting

I hope to get the same in-depth review of my new site (we're still working on it) when I post it here in a week or two. Despite my massive list, the site isn't all that bad, hehe. I basically listed things as I saw them.
Don't really like the scrolling text at the top, nor the not-quite-just-a-keyword-list at the bottom. It's not too bad, but still looks too much like a list of keywords to me, plus it's barely readable with the only slight contrast on the gray. The links at the bottom are worse - blatently for boosting search ratings, and they don't even work correctly. Same with the list of links on the site map... It's not worth the possible increase in search engine results for the risk of being blacklisted and the drop in professional appearance.
The blue on the gray for the titles of the left looks pretty off too, and even harder to read is the blue on the dark gray at the top navigation. The visited link color is even worse.
You'll want to make a single css page that is linked to by every page, instead of having the css on every page -- this is much harder to upkeep, and makes loading times much worse for dialup (2 extra seconds for every single page). I'd definately recommend looking at some kind of more dynamic setup (such as php based) instead of the hundreds of single html pages. (I imagine they are auto-generated, but doing that every time you make a change is really excessive and tedious it seems to me.)
The 'click to enlarge' pictures seem kinda silly when they're not even 50% larger than the pictures they're enlarging
The FAQ is hidden as it's only linked from the bottom. You probably want to specific what the money-back guarantee is _for_ (e.g., against defects, any dissastisfaction, etc.), how long it's eligible (such as 30 days), etc. Looks kind of odd the way you say 'we offer 15 brands' and procede to list them, but only list 7; probably put a word like 'including' there. What times can you call the phone number for contact? Things like this are good info that people want to know I'd say. You may also want to suggest some shirt brands (such as Gildan Ultras) - an uniformed consumer would not know where to begin (The default ones on the front are good, but not really enough IMO). Also, what kind of file formats do you accept for artwork?
The 'help department' link doesn't work correctly; it pops up a box only showing html (and this html includes frames -- frames are bad news).
On the actual product pages, it seems kind of pointless that you have to click the customize button - it should pop up automatically when you select your color; that's only more step that slwos the customer down and keeps them away from the checkout.
In the category listing (and searches), the 'customize' and 'add to cart' buttons go to the exact same page it seems to me.
You still list 'sleeves' as options for doing pants and shorts - confusing.
There's no real way to see what sizes actually are; Is a 'Large' pair of shirts a size 34 or a 38, for example.
The colors and design need a little work as well, though I don't have any good specific suggestions there at the moment.
It's good to see you've got it compatible for 800x600. The customer testimonials are a good touch. The general layout is pretty good, and instant quotes are nice. The basic mouseover for links is good without being excessive.