The Armstrong And Miller Show on BBC1 scooped one of the early awards of the evening, for comedy programme, beating The Kevin Bishop Show, That Mitchell And Webb Look and Stewart Lee's Comedy Vehicle.
E4 series Misfits, about five outsiders on community service, won the drama series gong, with the cast joking that "juvenile depraved filth had been crafted into such a great Bafta-winning show".
Ant and Dec finally scooped their first ever Bafta – with their sixth nomination – despite a 20-year career in television.
The duo beat Harry Hill, Stephen Fry and comedian Michael McIntyre to the entertainment performance gong for I'm A Celebrity...Get Me Out of Here!.
Dec, 34, made light of how long it had taken to get an award, saying: "I really, really, really wasn't expecting that. That's a big shock."
Ant joked: "You feed a couple of kangaroo testicles to a glamour model and you get a Bafta."
The Unloved – Samantha Morton's close-to-the-heart directorial debut about a care home – scooped the award for single drama.
Mad Men, the advertising industry 1950s-set US drama broadcast on BBC4, scooped the international gong, beating the likes of Family Guy and True Blood.
Inside Nature's Giants – the Channel 4 documentary which showed the dissection of giant animals – won the specialist factual award.
Channel 4 Dispatches programme Terror In Mumbai won the current affairs award while ITV'S News At Ten took the News coverage award for its reporting of the Haiti earthquake.
Ant and Dec later presented the special award to Simon Cowell for his contribution to the industry and for bringing forward new talent.
Ant said of the Britain's Got Talent and X Factor judge and creator: "I admire him" while Dec joked: "I'm terrified of him".
Dec said: "Over the past decade this man has helped make ITV what it is today – still in business."
Britain's Got Talent also won its first ever Bafta – for entertainment programme beating The Graham Norton Show.
EastEnders was top continuing drama over The Bill, Casualty and Coronation Street.
Rebecca Hall won the supporting actress title for Red Riding 1974, for her role in the dark Channel 4 drama as the mother of a missing, probably murdered, child in 1970s Yorkshire.
One Born Every Minute, filmed on a maternity ward, took the factual series gong for Channel 4.
Rebecca Front and Peter Capaldi won comedy awards for The Thick of It.