I've tried the 2-3 well regarded Brick Lane "Indian" restaurants and I thought they were all pretty poor. My current favourite is currently Kennington Tandoori, a sort of local curry house for the powerful. Last time I was there we sat next to the Speaker of the House of Commons and a former Chancellor of the Exchequer.
Dishoom was setup by a former colleague of mine and now has a few venues. They each tend to generate large queues, but the food is modern and very tastey and service usually of very high standard too.