3 tiers:
Fraternities @ MSU which are the better frats on campus and what reputations do they have now days?
Right now I would separate the fraternities into three tiers. Obviously it varies depending on what your looking for but I'm just going based off type of guys, parties, perception on campus, involvement, and what most girls flock to. Full disclosure I was a Sigma Chi (2010-2014).
Tier 1:
Sigma Chi: Best campus involvement, nicest house, overall considered the best by a majority of girls and has an incredibly diverse group of guys. Derby Days is great, and All Sig Day is a ton of fun.
Kappa Sigma: Recovering incredible well from the trouble they got into a few years back. Charity Bowl is awesome, and no party can stack up to South Seas.
Phi Delta Theta: Have been on social probation for what seems like the past two years, but still have managed to get a lot of great people to join. When they are off social probation their parties are notorious for being the most fun. I knew a lot of awesome guys in Phi Delt.
Tier 2: All these fraternities are great and depending who you ask could be easily placed in the top.
SAE: Have more of a druggy reputation but still are routinely really really good.
KA: I feel like they just keep getting better
Pi Kappa Phi: They are less than 4 years old on campus so still growing but have a lot of great guys.
Pike: Don't know much about them, but have always been good.
Tier 3: These are the best of the rest. Some fraternities aren't even worth mentioning.
FIJI
Lamda Chi
ATO
Sig Ep had really moved into tier 1 but they are no longer on campus, so unfortunately they aren't an option.
Once again this is just my opinion so take it for what it's worth. I'm not gonna act like I'm not at least a little biased.