What sort of venue do you prefer to play in and why?

I'm thinking in terms of singaround, folk club, open mic, concert etc.

I'd guess the answer will depend on your repertoire and location so:
I'm based in England and (attempt to) sing (and play) material that I'd think falls on the "traditional" side of the great Mudcat gulf, (although it ranges from Child ballads to modern things like Dougie Maclean and even some of my own stuff.)

Singarounds suit me best; I like the feeling of community, the way you can join in with some of the songs and the way that, sometimes, those joining in with you can lift your own material. The downside is that your choice of songs needs to be a bit reactive if you want the singaround to work (listen to what others are doing and make sure you complement it to vary and balance the evening etc.)
Folk clubs are next; a bit like a singaround but more formal and less "we're all in this together" with a slight barrier between you and the "audience".
Concerts allow you to develop your set of songs (quieter and more contemplative ones in there but still leaving them humming the choruses as they leave), which can be nice, but I don't like the idea that you are there to perform and entertain a largely passive audience (see the discussion as to whether others should join in with refrains) – I miss the "we're all in it together" feeling.
Open mic venues don't work for me at all; they have the division into performer and audience of a concert without long enough sets to carry the audience through a range of emotions. (And, although I may be wrong, I get a feeling many of the performers are only there to do their own spot and not to listen to anyone else.) I also don't think my songs would necessarily entertain the audience as other performers do more "contemporary", American and blues styles.

So that's me. I don't suggest any one is better than another (it's all live music after all) and some of my perceptions may be skewed by my reluctance to be an "entertainer" rather than someone who just gives the songs an outing from time to time - but I'd be interested to know what you prefer and why.