My dad is visiting and wanted to take him to a few nice restaurants (since he's paying!). I basically went through the Michelin stars list and booked the newest places that I haven't yet been to, i.e. Alyn Williams, Trishna and Medlar.
I've been to Alyn Williams - had the tasting menu and was very impressed with the food and service
Trishna to be honest was a bit overpriced - I'm never that impressed by the Michelin Indian places as I think the cheap places do it just as well. Benares is the best of them IMO.
If i want really nice indian in London i usually just go to Sagar in Hammersmith - vegetarian, and all delicious chaat-style street snacks. A nice change from the usual korma / madras / biriyani