Welcome to FT.
You have a number of good options out of IAH. As jkirk mentioned, EK is supposed to be outstanding.
LH is superb in F. And, if you make a halt in FRA, you can try out their First Class Terminal, which is also great.
AF is pretty good. Don't know how good the connections are to India.
BA First is also very good. If you look at the individual airlines' flyertalk sites, you'll get a good feel for their +s and -ses.
The US-based carriers don't offer a true F class to India out of TX, except for AA, which flies ORD-DEL non-stop.
The general mood is that for most of them, the F experience has been diluted by cost-cutting. This is the complaint of those who have flown in F frequently. This may be true, to some extent. However, I think it is most noticeable on the US carriers.
If you don't mind connecting from to the West Coast, SQ and CX are superb!
But, it's still a lot of fun sitting at the 'front of the bus!' Enjoy the ride, and say: "Yes, please," to all the nice things they offer to you.
Please post your experience after you have completed your journey.