Develop 100

Develop recently published its Develop 100 list -

an annual guide to the world's most profitable developers, based on UK sales data collated by Chart-Track and ELSPA.
Next-gen.biz has a run-down of all the studios featured. The empiricism of this approach makes the Develop 100 much more interesting and unpredictable than other more subjective guides to the 'most important' studios - it is all about money, not reputation or the perceived quality of the games on offer.

As such, there are plenty of surprises. While several generally respected studios lurk in the lower recesses of the chart the top 30 features a number of comparative minnows. UK veteran Travellers Tales, for example, claims the number nine spot thanks to its wonderful Lego Star Wars title, while The Collective takes 15 on the strength of just one title, Star Wars Episode III.
It's interesting to note that there are 31 UK companies in the chart, suggesting that the domestic industry is a lot healthier than we are often led to believe. Alright, so aside from big names like Rare, Rockstar North and Criterion, some of these companies may not leap immediately to mind when we're thinking of truly world-respected studios. Plus, more than a few are lackeys to, or local offices of, foreign giants (EA Chertsey, Sony London Studios, etc), but it's clear Britain is still a key player, a hot-house of competitive development talent.

http://blogs.guardian.co.uk/games/archives
/2006/04/19/uk_studios_fare_well_in_develop_100_list.html