Rich is having enough money to do whatever the **** you want, without ever having to check your balance first. The exact number depends on the person. For me it'd probably be around 100 million, just because I love to waste money. I could live in comfort for a lot less, but when I'm rich, if I have the random urge to go to the most expensive hotel in the world, spend a week in Dubai doing whatever looks interesting, and drinking 60 year scotch until I pass out every night, I wouldn't eve have to think twice about a budget. I wouldn't need to OWN very many big expensive things,it'd be more about having access to entertainment opportunities on a whim. For my own needs, a house that cost a few mil, a 10000$ computer, big TVs and that kinda crap would be all I could ever want. Being able to upgrade my machine without a second thought when new parts release without thinking "You know, I want that, but I think I'll wait until the price falls into the triple digits".

Would it change me? Sure, I'd be a lot more pleasant if I didn't have to work for a living.

Would friends want something? They probably would, they might benefit from it, but I wouldn't be giving handouts without cause. Might invest in a few friend's futures if I think my money would help them make something of themselves. Mostly it'd just be inviting them along on my overpriced vacations. Probably have a few move in with me, just because why the **** not.

Would I want something? No more than I'd be willing to give if it were me. Of course most of my friends would probably offer more anyways, and I'd accept.

Buy a huge house somewhere with a good 1gig internet service available (I've gotten too used to mine to ever live somewhere where it wasn't available), and turn the basement into a man cave the likes of which the world has never known. Get a few 90 inch TVs, one for TV, one to use as a monitor. Put a master bath in the basement, with one of those awesome0 rainfall showers, and a huge hot tub in the middle of the bathroom. There'd be a bar in the basement, stocked with a bunch of whiskies I've always wanted to try. I really wouldn't even need the rest of the house, aside from the kitchen. I'd just live in my own basement and move a few friends in to the bedrooms upstairs.

Aside from the house, probably a really expensive antique weapon, like a kamakura katana or something. If I could track down a legit Masamune or something from his student, Go Yoshihiro, I'd buy it.

If I were to become rich, it'd either be for some major invention or discovery, or a string of high profile assassinations. I don't much care which.