It's a term oft-used, but what for you constitutes mind blowing sex?
I shall start (guy obviously) - I need intimacy to be able to really enjoy sex, and the best sex for me is being able to shower my sexual partner with ripples of pleasure and steadily increasing, repetitive, waves leading to strong orgasms. My OH can squirt so when she's been especially good/bad I encourage her to go wild and soak the bed.
It's strange as a guy but PIV is simply a means to an end, I much prefer the variation that comes with extensive, long lasting foreplay, and building things up through various oral techniques (licking the wishbone of the clitoris produces good results), fingering techniques and targeting the four or five main erogenous zones inside the vagina. Then there's multiple toys - Doxy wand, we-vibe tango and lelo ella are essentials - and PIV/PIA.
So, what's mindblowing about sex for you?