I think for summer tyres, the majority of folk on here recommend the usual: GY Assy 2's, Michelin PS3's etc as they all provide a great balance of performance vs cost and suit the car well.
The Auto Express tyre test with the mk5 GTI tested all the top brands in a variety of conditions, wet & dry cornering, braking, acceleration etc and favoured the brands listed above among the top performers.
For winter tyres - the general concensus is that any brand of winter tyre is better than even a top brand of summer tyre (based purely upon the reviews on the forum).