I second, I will be a junior at ND (I transferred in after my frosh year) so if you have any transfer or ND questions feel free to send them my way. You can email me through my profile.
Alumni isn't bad, I have a lot of friends there, but the rooms are very small! Be sure to keep that in mind when packing.
Most of my female friends are in Lyons and they love it. It seems to have a good amount of spirit, is a nice dorm, and is in a good location (as is Alumni, I am partial to South and West quad). Both dorms get my thumbs up (they aren't Zahm, which helps) but really all the dorms are pretty good!