I've seen people say this is the British version of "Friends", and a lot of people who disagree. I actually think it's a good place to start. There are (excluding Season 4 anyway) 6 friends, 3 male and 3 female. They hang out together in a bar near to where they live, and there is a reasonable amount on "in-dating" so to speak. So the general setup is similar.
Now, onto the best bit. Coupling is pure comic genious. I defy anyone to watch the first 3 seasons and not say that Geoff is the most brilliant character ever written. If you're drinking anything when he starts talking about "The giggle loop", "Porn jelly", or "Captain subtext", be prepared for it to come shooting through your noise in fits of laughter.
Such a shame it finished so soon.