I use a variant of a Card-Based system I saw on here.
You have 12 cards: 4-9, in 2 suits.
Because I like a little bit of randomness, I replace one of the 5s with a joker.
Shuffle the cards, and draw pairs.
Add the numbers together.
It gives stats in the range of 8-18. It essentially ends up with something comparable to a random point buy. Nobody can ever have more than one eighteen. Also, noone can ever have more than one eight. The limited number of each card makes this work.
The Joker doubles whichever number it is paired with, making it slightly more random. as the above gave too similar numbers each time without it.
The average stats go from 10/11 to 12/13. I tend to up the DCs of spells and poisons vs the PCs by 1-2 to compensate, as well as raise enemy AC by 1-2, as they were plowing through everything because of their superior arrays.
But I really like the effect it has on the players abilities in comparison to eachother so I keep using it.
I also use a different ability score progression by levels, which I end up using on NPCs as well. The Players like the added flexibility.
Every 3 HD you get ability score increases (instead of every 4). You get 2 of them each time instead of 1, but they have to go into two different attributes.
Half my players really like it, one dislikes it, and the other 2 don't seem to wrap their heads around how it works enough to be able to tell the difference, beyond the fact that they find it harder to understand.
It's a really non-standard way to do these things, but I found it, liked it, and adapted it, and I don't plan on going back to 4d6 drop lowest or point buy.