Whitby for me too. It is spread about the town, so lots of climbing up and down the cliff and waiting for the harbour swing bridge so that we can run from Dance Workshop to pub Music Session, to Concert.
Loads of participation. Not so many fashionable 'big names', but more of 'my folk heros'. You can learn to do almost anything folkie, I arrived early for a session and found myself with a set of pipes stuck under my arm once.
The thing I like is the range of expertise catered for. Some dance workshops raise your standard because you are dancing with so many experts. There are music sessions for experts too (some in pubs only known by those who know), but also 'slow and steady' sessions and even a 'not quite ready for a session' for those who would get left behind.
I've given up going to the sing-arounds, you have to get there early to get a good seat, and we are too busy dancing to get there early.