My memory isn't great on things like this but from what I remember, the best this season (not in order) were:
Man United - They came across like Palace or Portsmouth with their wacky songs at 0-3 down, but they can only support their team and that's what they did.
Villa - Seem to remember them being fairly loud
Spurs yesterday
Young Boys in the Europa League also got behind their team well too.
Just a mention on our away support. I don't think we're as good as some in terms of constant backing with chants, but I can't think of a better away support in England this season when you take in to account size of following taken away based on football served up. Our fans were expecting a top 4 challenge, and a Europa league spot at the minimum and we've sold out the maximum allocation at nearly every away this season. A lot of similar sized clubs in our position wouldn't have done the same. Spurs fans were pissed off and took 1,900 to Burnley at one point whereas we kept selling out. The most impressive was the 3,000+ we took to West Ham with 6 days notice in a horrendous spell of form.