For me there is always doubt over any sitcom, or perhaps any comedy in general broadcast on ITV. Their track record just doesn't match the BBC in recent years. However, watching 'Shane' I found myself laughing almost constantly.
Admittedly 'Shane' is almost totally a vehicle for Frank Skinner to deliver more of his one liners and occasionally dirty jokes and it relies upon these a lot more than the plot, which is never strong. However, the supporting cast (none of them are any more than that) do a really good job, with special mention going to Shane's son, who seems to have grasped the art of comedy at a frighteningly young age.
'Shane' isn't really a sitcom. It is just a different form of stand up comedy for Frank Skinner. Even without the basis of a good plot it works, purely because Skinner is a very funny bloke. I don't know how someone couldn't find 'Shane' even grudgingly funny.