I did my MS at WSU and the two years I was in Pullman were amazing!
The campus is beautiful, but a bit of a pain in the winter with the hills and snow. But that was because my building was off the main hill and the libraries were on the hill. So overall, it was a minor issue.
You will need to get a parking pass if you want to park on campus. Where you park and how much you have to walk will depend on how much you want to spend and where your building is in relation to the parking lots. They don't over-permit as far as I'm aware, and you can always park "down" a permit level if you need to, you just can't park "up."
Cougar Football Saturday is the best thing ever. I miss those days.
I had a pretty active social life with both students and townies. There's a lot to do and I was never bored. I participated in a darts league for a good portion of my time there, and Tuesday nights at My Office were often the highlight of my social week. It's all about making the choice to be active, though.
I was a TA and had a great time doing that as well. However, I know some other grad students absolutely hated it. It really depends on the classes you get assigned and how the Prof. is with utilizing your time well. Some TAs ended up spending 40 hours a week grading and teaching, while others spent 10 hours. So really, that is going to depend on what you're teaching.
I did continue on to a PhD after WSU and I was accepted into every program I applied for, at really good schools. WSU's reputation was just fine for that. People on the East Coast aren't as familiar with the programs that WSU offers, so I've run into that a bit, but overall, it hasn't been an issue. But I'm also finished with my PhD, so that school is the one more people ask about at this point.
The grad school process at WSU was actually really well planned and laid out, at least from my perspective. The school where I got my PhD actually was a bit of a cluster in some respects comparatively. I had a lot of respect for how WSU did things after experiencing the process elsewhere.
The faculty that I interacted with were all really open and willing to interact with you outside of lectures/class. Most of your classes are going to be a lot smaller, which really opens things up for more interaction. There were many instances of going out to the bar to watch basketball games or just to hang out with a big grad student/faculty group. There was less of the student-professor barrier that you see in undergrad.
Overall, I loved my time at WSU and I wouldn't change the experience I had. I wouldn't be where I am now if I hadn't gone there for my MS. It was there that I pinged on the research subject that I wanted to do for my PhD, and thus chose my next school based on which professors were doing that research. In the biological/medical sciences, you more often choose your PhD school based on the strength of the program, and less because you want to research a specific topic. I had the extra onus of finding good schools with people who did do the research I wanted to do. I applied and got into Wisconsin, Nebraska, Cornell, Hawaii and Illinois-Chicago for my PhD.