Well , lets pretend you need to do both. Because after all I think you want trim toned inner thighs. I find that all leg exercises work the inner thighs.
Lunges are great.
I also find that when I do leg curls I feel my inner thighs if I put my feet together and squeeze when curling up. For losing fat that comes with cardio and eating properly. I hope this helps. Well , lets pretend you need to do both. Because after all I think you want trim toned inner thighs.