Old Trafford has improved. I'd happily sit/stand anywhere in the Stretford end, K stand (east tier 1) or even east tier two for a decent game now. They're all pretty lively.
Other grounds are so hard to judge, one thing I have learnt over the years is you can NEVER judge it off TV. I've been to a ton of games at OT and come home saying it was rocking, only to hear a mate/my Dad say it looked or sounded dead. So the same will be true of other grounds. Likewise when you're in the away end you can barely hear a thing in opposition.
Then context is such a big thing, turned up at Spurs new ground for the first time this year and it was absolutely dead. WHL used to be loud as feck, but we were pumping them 3-0 and they all wanted the manager sacked...Then you'll get Norwich fans turn up at OT for a 12.30 KO and say the atmosphere is shite - well yeh, it is for you lot. Ask Leeds how they found it.