Innovation stands out as one of my favorites. Each card is unique, the mechanics are fairly easy to understand. Every game plays out differently, and there's great player interaction - both direct and indirect. Best with 2, okay with 3, too crazy with 4.
Die Sieben Siegel and Sticheln are my favorite trick taking games. The former telegraphs your hand to your opponents, while the latter turns trump on its head.
White Wizard's Star Realms is a very approachable dueling game, and Epic distills the TCG formula while still being robust.
Blue Moon: Legends is Blue Moon but with normal instead of taro sized cards and you get everything in one box. Another game with tons of bang for the buck, this is Knizia's refined take on the TCG model. While there are a couple of icons, I don't think this game has any keywords. A dueling game of brinksmanship.
Codex is phenomenal. It has a completeness similar to Blue Moon, but is easier to "mix" custom decks (which I never do with Blue Moon). Since you can play with 3 factions at once, you just pick three of them and go. Think RTS meets TCG, this is marketed as a "card time strategy" game. I got turned on to Codex after reading the faction articles - check them out!
Hanamikoji takes a slim shared deck and gives each player 4 actions, each of which they must take exactly once each round. Like Battle Line and Omen: Reign of War you're attempting to control central areas by applying influence to them. Each central area (represented by an artfully drawn geisha girl) has a point value, and you'll win if you get the majority of them by the end of the round or if you get enough of the valuable ones to meet a point threshold (11 pts). What's beautiful about Hanamikoji is how deliciously interesting each play is. One action takes cards out of the game, one action hides a single card to be revealed later. The other two present your opponent with choices, in a "I'll cut the cake, you choose the piece you want" vein.
Haggis takes the tried and true play of the climbing game Tichu and removes the partnership aspect, making it play extraordinarily well with 2 and 3 players (the only numbers it supports).
