CO IAH-AMS, then AMS-NCE on AF/KL would be very nice, except for the poor connection time at AMS, at least in the current schedule.

Timing for CO46 IAH-AMS is one of the best for US-Europe. 7:10pm departure. You can get your full BF dining experience, and still have plenty of time to rest.

Only problem is that it arrives AMS 11:50a, and you can't make it on the 12:10p flight to NCE. Next one is at 5:55p.

Second best would be CO10 to CDG on the 772. A little earlier departure at 6:40p, but still decent. 11:05a arrival, and you can connect to AF at 12:40p. If you miss that one, there's another at 1:20p.