When I visited UC-Irvine, I came away with the sense that even though it was approaching the end of the term and finals, students were generally happy. There were lots of smiling faces all over campus. UC-Irvine is known for a number of things, including having the anteaters as their school mascot (a fact my tour guide was very proud of). They also have a strong Computer Science program, and as part of this, they recently opened an e-arena, where students compete in video games (there are even scholarships offered for this for a select few students), so they taking gaming seriously.
The UC-Irvine campus is very well laid out, with the main classroom and administrative buildings arranged around a large circular path, with a hilly park in the center. The set-up allows students to get between their classes quickly, and the weather is generally pleasant all year round, so the circular path seems to be a popular place to run into friends and classmates.
The campus feels quite diverse as you walk around, and with almost 15% international students, it is also quite geographically diverse for a state school.