I'm from Pennsylvania, so here are some hopefully not-too-biased observations on other parts of the country:
Colorado: Reasonable cost, great weather, lots of amenities, but I've heard Denver referred to as "Menver" so if your idea of dating pool skews X-chromosome you might be disappointed.
Portland: Maybe the high end of "cheaply" but lots of tech scene and indoor/outdoor amenities. I was ok with constant mist for the time I spent there but it might get to other people.
Upper Midwest/Upstate NY/New England: I can't fathom dealing with winter there but if that's your thing then it's probably great?
Portland, Oregon can be /very/ cheap if you live outside the city. And, if you live in a large 4br house with other people (or even just another person if you both make enough) you can get your rent down to $400ish if you live with 3 other people, $800ish if you live with one other person.
Colorado: Reasonable cost, great weather, lots of amenities, but I've heard Denver referred to as "Menver" so if your idea of dating pool skews X-chromosome you might be disappointed.
Portland: Maybe the high end of "cheaply" but lots of tech scene and indoor/outdoor amenities. I was ok with constant mist for the time I spent there but it might get to other people.
Upper Midwest/Upstate NY/New England: I can't fathom dealing with winter there but if that's your thing then it's probably great?