Sushi Go! is a fairly simple drafting game designed by Phil Walker-Harding. It is designed for 2-5 players, takes about 15 minutes to play, and is suitable for ages 8+; in my experience it is frequently played and enjoyed by groups of ages 25+, and remains fairly challenging.
Game play is simple, although plotting your strategy may not be. Each player receives a random set of cards (the number varies based on number of players), and they each choose one, reveal it, and pass the remainder of the set to the person on their left. Repeat until all cards have been drafted.
The trick is in the scoring rules, which are different for each type of card. Sashimi are scored only in sets of three; the wasabi scores only if paired with a sushi roll; the value of each additional dumpling increases exponentially; maki rolls are always scored at 6 points for the person with the most and 3 points for the person with the second most, regardless of actual counts; and so forth. Most of these are scored up at the end of each of the three rounds, but puddings are saved and scored at the end of the game.
The scoring system for each item is indicated on the card, but even so it takes a few rounds to get it down. Once you do get it down it is still fairly difficult to plan a strategy, as with only 7-10 drafts per round making the wrong choice before you see the other hands can be a serious handicap... as can playing it too safe, or finding that you and another player are gunning for the same resource.
Sushi Go! is pretty fun regardless, but it has three big things going for it that make it particularly popular in board gaming circles: it is good for odd numbers of players, it is quick, and it is comparatively cheap (~$15-20, depending on edition). It is a popular game to play while waiting for the rest of the group to arrive (or finish playing a game), or to finish off a gaming session when you are short on time but still want a fun cap to the night. It doesn't hurt that it is easy to learn and has cute little sushi roll art, either.
Sushi Go! has one follow-up edition, Sushi Go Party!; this is an expanded version of the game, with enough cards that you can play with up to eight players and extra types of sushi so that you can adjust your play deck from game to game.