I have travelled to UK from India many times and in different airlines. But I had always kept my first option as Emirates. As in anything here is also good things and bad things to tell about.
BAD
Checkin couters are not so friendly. Any how I have not got trapped for carrying any excess luggage yet. I have seen that they are very strict on the luggage. This is not really a bad thing but distresses a person on the start of the journey.
Legspace is less when compared to Jet Airways or other Indian operators
Good
I have not experienced too much of bad things. Cabin Crew are friendly enough. For food, if we do not prefer Emirates would consider as Non-veg and you may be served with any non-veg item. I dont mind that being a non-vegetarian. As my wife is a vegetarian, we had preferred for Asian vegetarian and she got Indian vegetarian(Poori/Masala).
And for the cleanliness, I have seen that the interiors and the toilets are kept clean through out the journey.
The inflight entertainment is equally good as any others for the matter that they have good collection of Bollywood and regional movies.
Emirates is also having good connections from Dubai. I had also seen good co-ordination and support to us when Chennai - Dubai flight arrived late and my connection flight was just 30 mins short to depart. the ground staff directed us in a separate channel avoiding the long queues helped us to board the connection flight.
I would suggest who is fly to Europe to try Emirates as they flies to many of the europeon cities.
Forgot to mention, I have been only an economy class traveller in flights so far.
Also, you get to see the Dubai Airport Terminal 3 which is a great place to so shopping.