Kamen and Ottman both have similar main themes. Ottman's theme is pretty much the John Williams version of Kamens. But both pretty grand.
Kamen was also the one who decided that strings work best for Mystique, and Ottman continued that with her X2 theme.
Honestly, I miss those God damn strings.
Powell's music is when the drastic shift occurs. And I like some
of it. . .
But the most iconic piece of music, imo, is Jackman's Magneto theme from First Class and I will be DEVASTATED if we lose that.