Metroid: With the exception of...certain...recent entries...I've held that Metroid is like Zelda, but for adults. The atmosphere, sense of isolation, and amount of skill required from the player are all ratched up a notch, and it tends to be far less predictable than its fellow Nintendo series.
Ace Attorney: One of the few series left that really puts a lot of effort into its writing. The characters are well rounded and funny, the mysteries are always enjoyable, and the games do an excellent job of interjecting just enough humor to avoid being too depressing while simultaneously keeping a consistent tone.
Devil May Cry: On the complete opposite end of the spectrum, Devil May Cry hardly cares at all about writing and instead focuses on creating ridiculous combat scenarios. Unlike its hack and slash rival of the day, God of War, Devil May Cry has a much more expanded list of moves, allowing for the player to pull off long and varied combos, which makes it the far superior title in my opinion.
Fire Emblem: Fire Emblem was a series that surprised me, mainly because I've never been a huge fan of turn based combat. Entertaining and (usually) solid characters, as well as a clearly laid out series of maps and a number of additional rules allow for more than enough complexity to make it entertaining.
Super Smash Bros: I tend to have a thing for games that appeal to both casual fun and competition, and Smash Bros does that better than arguably any other game series. It's the perfect game for a random night with 4 buddies (assuming you can find that many who want to play), or for an actual contest of skill.
