Point-and-Click Games on Steam

The entire telltale collection should be crossing your mind, I bought it because I love point and clicks, and so should you, if you like them (it can easily be bought at sale price or lower in the trading market, 50%+ off the steam price if you're not a russian of course, then you already got way less then sale price..)

Going to second the King's Quest Collection. You don't get any more classic in the point and click adventure genre than Sierra games and $20 for 7 games is pretty good.

If you don't mind getting games from GOG, I think they have the other Sierra games over there for good prices.

I think he likes point and click games since he played Monkey Island and others LucasArts games, so I'm not suggesting them.

Try Broken Sword and Monkey Island series, both are great.

Sierra games like Kings quest, Space quest and Police quest are definitely classic adventure games, but they are very different to point and click adventure games.
They were the original graphic adventure games, but a lot of the time you have to type the exact phrase to do everything ('get stick', 'use stick with fire', 'use burning stick with cave'). It is easy to miss important objects then realise later in the game when you cant backtrack any longer.
All of the listed point and click games (monkey island, broken sword, indiana jones, the dig, etc.) have their list of verbs, to combine with your inventory item to then perform actions. This interface is much more user friendly than the original 'type everything' interface

Eschalon: Book 1
Eschalon: Book 2
Neverwinter Nights 2 - Nevermind, it's apparently not available any more :(