i think it's not so much where as when. feb half term is expensive. i would try the big names (crystal thomson inghams) and the big resorts - soldeu, pas de la case. i haven't been, but i believe they have excellent english ski schools, very friendly kiddie runs and excellent off-piste if you know where to go. i think a lot of the ski schools start at 6 though, so i can't go yet (because of children not because i am 4!)