Saving for retirement

Root of Good - This guy retired at 33 after years of high savings rate and low expenses. In the world of Financial Independence/Early Retirement (FIRE) he's definitely on the milder side.

Mr. Money Mustache - The OG FIRE preacher. He's basically a mid-aged software engineer that earned a ton of money and figured out that if he lived a reasonable lifestyle he could stop working. He big proponent of the 25x rule (often referred to as the 4% rule), he's a bit extreme in some of the things he does. He's also turned his blog into more of an income-stream vehicle rather than being purely FI.