elchebib wroteNemesis-301 pretty much sums it up.
Go for the PS3 if you really care about online play. Personally, online play is fun and does extend the playability of many games. Granted, our internet connection in Lebanon is horrendous but nevertheless, you will get to play some decent online matches. In addition, there is a huge lebanese online community so you can play with them. However, you will have to pay upward of 70 USD for each game (which I don't consider a negative since you'll be supporting the developer).
Go for the X360 if you don't care much about online play. Its not that the X360 online capabilities are bad, its because you can't find original games in this country and if you go online using a pirated or modded console, you'll highly risk your console being banned and the only way to fix this is by buying a new console again. There are places that sell original games but their stock is usually very old and usually they don't restock new games.
In terms of games, they're practically the same. Graphics, gameplay, variety of games. They're all the same. Prices are the same too more or less.
I say if he wants to get original games on the 360, then Xbox Live is really a good feature. Ok yeah you have to pay 50$ a year but you are paying for a network that doesn't crash, that always has people online.