I am not very flexible. Except my open hips. My hams and inner thighs are very tight so my spirals stink. My favorite stretch is something we used to do in ballet as a kid, that the instructor would always yell at me for. We'd spread our legs, lean forward, and try to palm the floor. I could never get my palms flat. Instructor thought I was being difficult. No really, I couldn't. And I was probably the only ballet student who couldn't do the splits.
In college, we used to do this stretch in colorguard. I really hated that I couldn't do this so I practiced and practiced and finally could almost get my palm down. Years later, I can palm the floor. So yea, that's my "favorite" stretch because it's my nemesis.