$1mil (before taxes) would be nice, but wouldn't even pay off the mortgage by the time I got to that. After tithe and tax, paying off some student loans, filling up the emergency fund, boosting retirement savings, and putting a reasonably amount in the kids' college accounts I'd have enough left to get my mortgage down to $100k, give or take. I think I figured $2mil (before tax) and after paying off the house along with all the rest of the above I'd have $250k left. With that I could see a couple of newer (but not new) cars and a vacation somewhere with the whole family. Maybe designate $5k or so each for the wife and I for toys, fix a few things around house, and then sock away the $150-175k still remaining for something later on down the road, or make it an extra boost to retirement savings.
$400+mil ($250mil ish after taxes)? Crap, by the time I did all of the above I'd still be round-off error from the full amount. I'd probably quit my day job so I could spend the time necessary to use that money to do the most good for society possible. Which would mostly consist of trying to find ways to annoys leftists.