Geeky Jay

I really like rss guard. Obligatory "I'm a Linux user but this software runs on windows" but I've seen it on windows actually, it looks quite nice, but I'd warn that if you have a particularly large monitor, the text looks pretty small. I don't know if I'd call it the best, but it's my personal favorite I've used so far. On android I've been kinda looking at twine, but I realized I don't really enjoy reading stuff on my phone as much so I haven't gotten enough use out of it to say whether or not I'd recommend it. It looks really nice though.

i use fluent reader, it's available for every platform but i haven't tested it on mobile. if you intend on syncing between devices you'll also need a service, and i heard good things about inoreader for that