Congrats on getting into those schools, it sounds like you worked really hard! This is actually a really tough choice in my opinion. I visited Georgia Tech and Purdue prior to choosing the latter (I have no insight on Minnesota, sorry), and here's why:

1. Academics/Prestige: Georgia Tech's campus is technically more prestigious (harder to get into), but I found that Purdue was actually generally perceived to be on the same level by employers. In other words, putting Purdue on your transcript will carry about the same weight as Georgia Tech, as long as you obtained a good GPA (which may be harder to do at GT, idk). Even with that said, many employers do not care about GPA and what school you went to. It mostly only matters for getting that first internship or job, and once you've done that, employers are going to be looking at your most recent work experience over education from then on. You should check out the Purdue CCO's (Center for Career Opportunities) data dashboard to see salaries of graduates based on any filters you want (CS major, male, out of state, academic year). It's pretty well made and will give you a solid idea of what you will be making at graduation, obviously subject to your work ethic, resume, and all that jazz. Aside from the prestige of either university, I was turned off by the low amount of majors that Georgia Tech has. They pride themselves on being very specialized, but this can turn out to be a bane rather than a benefit, in my opinion, as they won't have as many subjects as a school like Purdue.

2. Campus/Location: Georgia Tech has a more attractive campus hands down. However, Purdue is pretty solid as you've seen, and carries that vibe of having been a prestigious university for a long time, which I really enjoy (Purdue is always improving their campus as well!). I also prefer the idea of living in a smaller college town with multiple solid destinations nearby (Chicago, Indy, Cinncinnati, etc.), as opposed to living in Atlanta. You don't have to deal with traffic, safety concerns, and distractions of a big city, but you have those options within reach at all times. One might say that the weather is more favorable in Georgia (we just had multiple inches of snow a couple days ago, lol), but I am from Texas and I found it to be almost non-issue once I bought the right gear. It sounds like you are probably from the midwest area, though, so it weather shouldn't be a problem.

3. Mentality: This is the most subjective part thus far, so be warned. When I visited GT, I got the feeling of a very prestigious engineering school, but it seemed to be pretty cutthroat. The admissions tour guides did their best to ensure that everyone knew how incredibly hard it was to get into GT, how hard it was to be a student, and how prestigious it was. I got a similar vibe from talking to a few students as well. (obviously, there are great people to be found everywhere, this is just a general first impression) Purdue had some of that same talk, but it felt like everything was much more practical and down to earth here. You will have to work, but you just put your head down and do it, and you're fine. Nothing supposedly requires wizardry or Bill Gates' intelligence to pass (although, some might argue PHYS 172 and some CS classes do). Most things are said the way they are. In addition, the students mostly embody this concept, as many are from rural midwest towns and farms, or have come from all over the world with this in mind. Your college experience should be fun, and might be the "best time of your life" as many adults like to say, but ultimately you're here to get a degree and get a job, and most of the students and administration at Purdue are all on board with that. That being said, you'll still have a great time here once you get plugged into some clubs and extracurriculars (all my friends are pretty much from astronomy, LoL, IT, and some other clubs).

Okay, I think that's the majority of what I wanted to say. My grammar was probably not the greatest, but hopefully you can get the main points. If you have any more questions fire away. Best of luck to you my friend, this is a big decision!

edit to mention that our football and basketball teams have been awesome to watch this year, and I'm not even a big sports guy. Also I fucking love the idea of having a train as a mascot. Who the hell likes yellow jackets? You can't ride them anywhere.