I've been using MP3tag
(similar sounding name as above, but not the same) for a few years. I've tested it on Zune, WMP, iTunes, and foobar2000 and they all seem to display properly. It's updated fairly frequently, and it works on Windows 7 Pro x64.
2600K @ 4.8GHz; XSPC Rasa/RX240/RX120 Phobya Xtreme 200; Asus P8Z68-V Pro; 16GB Corsair Vengeance 1333 C9; 2x7970 OC w/ Razor 7970; Force GT 120GB; 3x F3 1TB; Corsair HX750; X-Fi Titanium; Corsair Obsidian 650D; Dell 2408WFP Rev. A01; 2x Dell U2412m