I would go with the cheapest and/or the one most convenient to your needs. All three have cramped seating, Virgin staff seem to like to gossip rather than work and their seats are really hard. BA normally have reasonable food and professional staff but their entertainment system is the worst of the three. A few years ago I would have chosen Emirates but I believe their product has gone down hill and can be a bit of a hit and miss affair.
You might want to check out Etihad although they fly into Abu Dhabi rather than Dubai.
check out http://www.airlinequality.com for reviews on all of these airlines.

I agree with Judith. You may wish ofcourse to fly on the Airbus 380 which Emirates operate on certain flights from Heathrow. Does not necessarily mean better service or additional space around your seat but is a bit of a novelty at the moment.

Nivsy

PF1234,

The Other Question To Ask Your Self Is Are You Part Of Any Of Those Airlines Rewards Schemes.

Gower