I actually (part)own and operate a board game convention.
Yes, I know a few things about them. The thing with board games is that it's a lot like vehicles. There's a ton of different "types" of games, and then within those types, subtypes, and then within that there's a billion different choices.
Ticket to Ride and Dominion are two of the more approachable games. Ticket to Ride is a very easy, fast and casual game. Dominion is a card based deck builder where you essentially are playing solitaire with 4 other people and trying to build up an economy in your hand where you can buy value cards. If he likes superhero themes, then look at the DC Deckbuilder. It's very easy to learn, and plays fast. Carcassonne is another very easy to pick up and play game. It won't set you back much money either and has tons of expansions to keep it fresh.
If he's not competitive and likes to co-op with others, then take a look at Forbidden Island/Desert. They are fast playing, coop games. Pandemic is basically the same mechanic as those two except it's a race against infections instead of sinking islands and you are trying to cure diseases. The choices are a bit more abstract and it's a much more stressful game, but very fun.