We're more than halfway through the latest series of Gavin and Stacey and so far, hardly anything has actually, you know, happened. But that's all to the good, because I reckon this is the funniest, most warm-hearted sitcom on telly for ages.

What's great is that all the characters in the series are likable, with even the more overt comic characters like Uncle Bryn and Nessa being fully rounded and sympathetic, without simply being used to set up jokes. The performances are exceptional too - James Corden is a great comedy actor and lights up the screen whenever he appears, and although some people seem to be finding Joanna Page a bit annoying, I think she's playing it just right, and her accent just makes the lines funnier.

Gavin and Stacey, back for its second series on BBC Three, continues to pose the question: who are the real stars of this thing? The pair were back from their honeymoon in Greece. It was "nice". But who wanted to hear about that when Stacey's friend Nessa still hadn't told Gavin's friend Smithy that she had his bun in her capacious oven? Mathew Horne and Joanna Page play the nominal leads with such Christ-like modesty that one feels vaguely aggrieved on their behalf that the best lines are written for Smithy and Nessa by the very actors who play them.

Mind you, James Corden and Ruth Jones came up with some crackers as they elaborated further on Nessa's extensive "Past". It turned out Nessa had driven the lorries for The Who's world tour. "Until I found out some things about Pete Townshend I didn't like. All I'll say - and I said it to his face - is where's the book?" This comedy is less mild than it looks and even funnier than I remembered.

The first series of Gavin and Stacey was a fairly low-key affair: a BBC3 sitcom about an Essex boy and a Welsh girl falling rather sweetly in love, with the comedy left mostly to their families and respective best friends, Smithy and Nessa (James Corden and Ruth Jones, the show's writers). Before long, though, that same low-key series started to win one entirely justified award after another.

So, the big question on the programme's return last night was how it would react to its own success. The answer, happily, is by not changing much. At times, Nessa and Smithy did seem slightly exaggerated versions of their original selves, but not enough to do any real damage. Otherwise, there was the same winningly good-natured tone, and same clear-eyed tenderness for the characters. Above all, there was the same joyous preference for finding the comedy already present in ordinary life (ie from basically nice people doing their best) rather than inventing some wild sitcom version purely to get laughs.