Hi Candiceena,
I've always dealt with this problem as well. It seems my hamstrings have always been stronger than my quads, and anytime I work my butt or hamstrings they get super worked up. I'm always thinking, settle down hamstrings! Gosh!
Anyway, maybe try the foam rolling again? It's by far the best thing that's worked for me. If you've been doing both legs at the same time, you can try doing one at a time to get more weight on it, and make sure you go really slow and pay attention, so that you can zero in on where the tight spots are.
Aside from that, I do a few things.
I stretch regularly (after workouts, but also every morning and every night). I do a modified sun salutation series, and I believe it's that regular stretching that keeps things loosened up, before I even get to my workouts. After a workout, I
never do only the stretch presented at the end of the dvd. To me they are completely insufficient. So I will do the stretching in the dvd, then also do my modified sun salutation series, then I do the 'standing stretch' series that's found in the 'Squeeze' workout dvd. If you want to try either of these let me know and I can give you the details. (I know you like barre workouts though so if you don't have Squeeze yet, get it!
)
I also walk to work every day (4 miles total) and I definitely notice on days that I don't, that I'm quite a bit tighter. I think getting that warmth in my legs (without it being an actual strenuous workout) helps to keep things loose.
Years ago I had a knee injury and I was told that my hamstrings were outbalancing my quads, but since then I've strengthened my quads quite a bit and I don't know, maybe it's improved some but I still definitely get the tight hamstrings despite my improvements in quad strength. Maybe they're still imbalanced.
This is a pretty long post, so I hope something somewhere in there helps you out! I know how frustrating tight hammies can be!