Way back in 1999 I received sales pitches from a half dozen investment advisors with charts that showed my initial investment would grow at 8% per year until social security kicked in. The portfolio would be valued at $1,000,000 by then. Surprise! It never reached that valuation with the biggest hit during the Great Recession. Actually the best performance longer term was the 6 1/2% per year return for five years when my retirement money was in an American Skandia variable annuity. American Skandia was one of many investment scandals over the past twenty years.
I’m thinking the best chance at becoming a millionaire is buying a half million dollar starter home in California. Once the valuation reaches a million, cash out and retire to The Villages.

Buying and holding coastal residential real estate in SoCal has worked for me. The home I purchased there in 1996 is currently worth about five times what I paid for it in 1996. Although I have used it as a personal residence I could have rented it out and bought other properties I suppose.

The best story I have heard is about an Air Force Academy grad who as a first lieutenant back in the late 1960's - early 1970's was stationed at SAMSO (now known as SMC). He bought a home for about $40k, refinanced it the next year to buy another house to rent out as it was then worth $70K. He kept going in this manner until he owned 21 rental homes in the Torrance/Palos Verdes area. He retired after 12 years seeing no point in continuing to work anymore. Those homes today have to be worth at least $1.5M each. I don't know if he still owns them...