I'd recommend starting with a half size down
934750
Overall decent.  They run a half size too large so my feet slide a little in them.  And I have just about the most average feet on the planet.  I'd recommend starting with a half size down.
1870842
I would recommend buying a half size down! Ordered a size 8 and they were literally slipping off my feet, had to put extra soles to make them fit better.  Other than that, they are very comfy.
594584
I took Danners suggestion and went down a half size.  I got a good fit. Right toe box has noticeably less volume than the left boot, however this did mot compromise the fit.
4354466
I really like these shoes.  I wish Crocs made half-sizes though, because I feel like the fit would be perfect if I could go a half-size down.
2644748
Look great, very happy when they arrived and immediately put them on. I didn't heed the warning about the size because some people these shoes fit true to size, putting them on, I probably could have gone a half size down if I wanted a tighter fit ( I wear an 11 in women's normally and I ordered a men's 9, but I could've gone down to a 10.5 women's/8.5 mens) but they don't feel too lose as if they will fall off when I walk or like I'll trip on my face because of the front sticking out too much. I'm not going to return them because it's not a big deal, the width fit perfectly and I got medium width (I don't think you can order a different width on this pair but I don't know I haven't looked) and I have skinny-ish feet but medium width is what I get in every other shoe I wear. So my suggestion is try a half size down if they have it and if not, go a full size down if you care about them fitting just so. Overall, I love my chucks and that's all that matters to me.
1251019
Overall great shoes! I wore them for the first time while walking around a new city and found them to be very comfortable even with the lack of arch support.. I usually buy an 8 or 7.5. I went with the 7.5 after reading other reviews, they fit fine with a pair of socks but I still could've gone down a size. Highly recommend buying at least a half size down.
917547
I really love the look of these shoes, they're really comfortable and look cute with everything. Definitely order at least a half size down. I ordered my regular shoe size, and even after putting in thick insoles, they are at least a half size too big. Without the insole I might even go a full size down.
1981112
I would recommend going a size smaller.  The boots fit like a glove and look great.
3624896
I sized down 0.5 sizes from 8.5 to 8.0 like many have suggested and found these Chukka's to fit really well. However, the leather is quite stiff in the first few wears and more persistent break-in may be required to get comfortable. The beeswax color begins kind of a uniform dark brown, but it has since really brightened with wear and some nice lighter colors are coming through.

Overall a great boot, just be aware that they may be a bit stiff to start off.
3498968
The first pair was a bit too large but I reordered a half a size smaller and it fits well.
4094926
For me I need to go down half a size for Cole Haans.  These are really light but have a jute insole which is not mentioned.  Not a big deal for me.
152417
I followed people's advice and went 1/2 size up and they are a tad too big. When I first tried them on, it felt ok, so I threw the box away, but once I worked out in them, I could tell they were a tad too big. It's not too bad, as it is just 1/2 size, but I recommend getting your true size.
Overall great shoes!
2634256
I love all of my Keen shoes. That being said, I might have had less blisters and discomfort if I had purchased this pair a half size smaller.
4406
Definitely go a full size down. I followed this advice and at first I regretted it i BARELY got my foot in and it was absolutely killing my feet. But after 20 minutes wearing them around the house, they had already loosened up a good amount. I've worn them for a few hours here and there, and they continue to get better.
470046
Typically, I wear 11.5 D, Mens, and ordered a 10.5 after reading through the comments. These are definitely long and narrow, so it probably was a good idea to go down a full size. I also expect the break-in period to be a bit uncomfortable, but if the leather softens as described, they should fit well.

A thought on size: Since styles and brands have different tolerances, fit can be difficult to get right. I have a pair of Sketchers Wing Tip sneakers, 11.5 D, and they have a pointed toe, so my big toe when pointing up is an inch or two away from the tip of the shoe, versus these at 10.5 and my big toe is much closer to the tip. It's definitely narrower than typical, but I suspect that is by design to allow the molding to the foot during breaking them in, so they keep their form better. Even before breaking them in, I can splay my toes comfortably.

I'm looking forward to breaking them in.
309576
I would opt for a half size larger than usual in the future
2350172
MAKE SURE TO BY A HALF SIZE LARGER. As long as you do that, I think you will love these shoes as much as I do. They're comfortable and I love the look.