The Shoei XR1000 Patriot is a beauty... but I couldn't find it available anywhere in North America. I ended up getting the Shark RSR2 "Foggy Legend". Much smaller Union Jacks unfortunately (and I wasn't huge on having flowers on my helmet, oh well), but I ended up being sold on the Shark brand. I considered the Arai too cuz I LOVE the looks of it from the front, but I wasn't a huge fan of the amount of white on the back. Again, I realize that's a little picky coming from a guy with flowers on his helmet
I tried to attach pics of the Shoei and Shark to this post. Hopefully it works so you can see what I'm talking about. You can also get a great look at the Shark if you search "Shark RSR2 Foggy Legend" on youtube.
If anyone knows of more Union Jack helmets, I'd love to see them. (Being that my S3 hasn't even arrived yet, I've got hours to waste on the computer searching for gear.)