It totally depends on your lifestyle. For most people accustomed to living a big city lifestyle, with frequent dining out, travel, etc, I doubt $1mill is adequate, even factoring in some SS and 401k money. You move to some place in florida or arizona, join an expensive golf club, the wife is going to want to take a couple of expensive trips every year, say to europe, you have to pay for medicare supplemental insurance, the local taxes are high, etc, youare probably looking at spending $80- $100k a year.
The real wild card is health. You may be fine for 10 or 15 years, but what happens if you have some problems and have to go into a nursing home($100k a year right there)? Medicare doesn't pay for that, or assisted living. By that point your spouse can't handle things and has to pay to get everything done. Maybe both of you have big problems and need long term care. That $1 mill can evaporate pretty fast. That doesn't even account for your kids wanting loans, losing their jobs, etc and expecting you to bail them out because, hey you're rich.
A lot of you probably are assuming that making 8-10 percent per year is child's play. After all, there was that one year you made 60%. It may not be child's play in a deflationary world, with 1 % interest rates and no inflation to produce automatic albeit paper gains. It also might not be so easy when you are on the wrong side of 70 and don't want to screw with the market or don't understand it anymore. Why not let your daughter's husband handle it? He just got a job as a broker at the famed firm Shill Securities. Oops, he just lost half your nest egg. Sorry.
And don't forget taxes. Hint: they're going up, real fast if obama and his crowd stay in power. Your social security will be taxed heavily because, hey, you're rich. They'll probably impose a steep wealth tax on the...rich, of course. It's a matter of fairness and spreading the wealth. Why should some have so much more? That will certainly be a winning argument among the 40 mill formerly illegal immigrants granted citizenship. Deal with it, gringo.