What is your favorite roulette strategy and why?

I’ve been practicing and tinkering with different roulette strategy, what strategies do you like to play and why? (Give me any variations on them and what you play, i.e. even money, 1-12, etc.)
I’m very familiar with the Martingale system, I actually made $100 using it conservatively (cutting losses after four straight non-hits and throwing some single number bets and getting lucky.) But I do understand the pains of the Martingale system, that’s why I’m asking for others.