Great thread. Obviously, from the answers here it is totally a matter of individual taste and experience.
For me, I was always sexually adventuraous in my head...had some 3-some/4-some experience in college then spent a monogamous, MUCH less adventurous 25 years with the same partner. While I may have sex with slightly less frequency now then I did when in the long-term relationship/marriage, it is quite a bit more varied, kinky, open, etc. At 48, I learned to dance, learned that kink, bi, flirtatious, poly...were all words that I could apply to myself comfortably for the first time in life. Now 55, I'm looking for a perfect partner(s) to enjoy my sexiness with. The desperation of my dating years has been replaced by confidence, experience, and the dreaded M word "maturity"...and it's working for me!