Comedy: Frank Skinner, Pleasance, Edinburgh<br/>Andrew Maxwell, Pleasance, Edinburgh<br/>Alex Horne, Pleasance, Edinburgh<br/>Rhod Gilbert, Pleasance, Edinburgh

Sixteen years after he won the Perrier award, Frank Skinner is back at the Edinburgh Fringe in the Pleasance Cabaret Bar, a room with a dozen rows of seats and a stage the size of a snooker table. In theory he's dipping his toe back in the stand-up waters following a decade away from "proper comedy", but all those series of Baddiel & Skinner Unplanned have kept his bantering muscles limber, and if he feels uncomfortable about being mere inches from his audience, you'd never know it. It's like seeing a stadium rock band perform an aftershow acoustic set at a jazz club.

Even though we're witnessing Skinner up-close and personal, and without the benefit of TV lighting or make-up, there are gasps when he mentions that he recently turned 50. But his advanced years, in comedy terms, suit him rather better than the gold front tooth he's just had fitted, and there's a winning vulnerability to his admission that he no longer falls over these days: he "has a fall", and his friends ring him to ask if he's all right.

Not that he's quite ready to go gently into that good night. Away from the TV cameras, he wisecracks about paedophilia and masturbation before climaxing with a routine about "granny porn". It may have seemed like a low-key show, but for Skinner to take his customary filthy-minded attitude towards life into his sixth decade makes him something of a pioneer. Frank is as frank as ever.

Of this year's five If.Comedy nominees, I've already reviewed two (Andrew Lawrence and Ivan Brackenbury's Hospital Roadshow), and I missed two others (Brendon Burns and Pappy's Fun Club). That leaves Andrew Maxwell, a gifted Irish raconteur whose show, Waxin', is as casual as the title suggests. Maxwell slouches on a stool – which is a feat in itself – chortling as he recounts what he's been up to "since last we met". He's eased up on his usual philosophical and political enquiries, and if he didn't refer to his TV appearances, you could imagine you were catching up with your funniest old mate in the pub. But is such a mild, meandering show enough to win a major comedy award? I wouldn't bet on it. Which probably means I'm already wrong – the gong was awarded last night after my deadline.

The affable Alex Horne devotes his uplifting show to his dad's favourite hobby, birdwatching. It's a subject that's ideal for Horne's repressed, very English persona, but the topic itself matters less than the flustered way he bustles through the hour, constantly questioning and interrupting himself, and like a plate-spinner, trying to keep an eye on the audience, the running time, the props and his PowerPoint display. I don't know whether the show really is in danger of crashing to the floor, or whether it's all an illusion, but it makes for sparkling, Fawltyish entertainment.

Rhod Gilbert is not only buoyantly funny, but he also has his own unique mix of grumpiness and silliness. Setting most of your anecdotes in a non-existent town is one thing. Admitting that the town is made-up is another. But admitting that the town is made-up and then carrying on with baleful complaints about how miserable it is to live there takes Gilbert's sublime nonsense to a higher level. "I wish I'd never invented the place, to be honest," he laments, but I'm glad he did.