The obvious in my mind would be a wand of some kind. Its just such a generally useful type of vibrator, can be pleasurable for any genitals and comes in many sizes and strengths.
Less obvious one would be a cock ring if you are a penis wielding individual. They’re unobtrusive and can give you a further measure of control over your erection/orgasm. Can help is a number of different scenarios. So what about you folks? What is your toy you think everyone should try?

The Liberator Wedge sex pillow.
https://www.liberator.com/original-wedge-sex-pillow.html
It is hands down my most used sex toy. You might be saying “a pillow isn’t a sex toy”, but yes it is. It’s enhanced couples sex experiences more than any cock ring, vibe, or dildo ever could. Almost every time I have sex, I hear “Get the wedge” and I know it’s time for some serious fucking.
Yeah, it’s stupid expensive for a pillow, but it’s the only sex toy I have kept and used through multiple partners. There are also loads of cheaper knockoffs but I can’t speak to their quality as I haven’t used them. I swear I am not a rep for the company or anything. I genuinely love the product.
That’s a good recommendation. Do you have a sex swing as well? Would you recommend the pillow over that?
I don’t have a sex swing, but at the very least the pillow doesn’t require finding a good load bearing ceiling joist.
Good point. Even if the swing would be better, its not something everyone can or should have depending on their home
Plus the wedge is easier to explain if someone makes a surprise visit to your house