The HAF 922 is just about under your budget, and is a popular case known for being very good at cooling, however I think the HAF 912, which is about £20-30 cheaper is a more fully featured and modern case, altho the 922 is bigger. So if you like the way those look, those would be two options.
The CM Storm Scout also has a window, but can be a bit restrictive on GPU length, 27cm compared to 29cm for a lot of other cases at this price point. Which I have read a few times on forums has caused people problems.
The NZXT Tempest Evo has a window, I read a review at Neoseeker which kind of put me off it. But maybe it's up your street.
You can buy the side panel with window for the Xigmatek Utgard and that is quite a good case as well.
Looking for all the latest features (USB 3 front ports, swapable storage drive bays, I'd look at:
Antec DF-35 - $120
Antec 902 V3 - $110
Of late I have been building strictly using the HAF's and DF series and I'm at the point where I am hesitating to recommend the HAF 922 as it's are sorely in need of an update. The HAF-X is excellent (out of your price range) but I find the HAF's tool less features a bit flimsy. The "Fleet Swap storage bays on the DF-85 and DF-35 make like a lot easier.. Their cable routing and inlet air filters (remove, clean and replace in 5 seconds are very welcome additions. OTOH, the safety lock on the 5.25" drive bays can be annoying if ya swapping CD's a lot.