"If you were stuck on a desert island indefinitely with no internet connection, what game would you bring with you?"
This question may seem like it has a very subjective answer but I believe the one true answer is a roguelike. You might think that Final Fantasy XXIII - Chocobo Dance Time is your all-time favorite game and that you'll never get sick of it. But believe me, after the hundredth play-through you will. Only a rouguelike gives you the complexity, replayability, randomness and challenge to keep you entertained for decades. And it would probably take you decades to win Dungeon Crawl with each class, let alone messing around with undesirable race/class combos.
This is my roundabout way of saying I've been playing a lot of roguelikes lately and I'm going to list some them. I'm not going to define what a roguelike is, that's what Wikipedia is for. I'm also not going to bother discussing the Big Three (Nethack, ADOM and Angband). Plenty of people have done that already. And to be honest, I don't play the Big Three anymore. I think they've gotten a little overwrought and gimmicky. But that's me - I don't even like side quests in my roguelikes.
Also, I'm ashamed to admit it, but I'm an ASCII-ist. Yes, I can't stand ASCII graphics which I know means I'm definitely not cool in the roguelike world. But my first roguelike was Epyx's Rogue on the Atari ST which had actual graphics. It's really hard for me, a decade and a half later, to play a game with worse graphics than that.
But where I thought I could help is by spreading the word on some of the lesser-known roguelikes. This list isn't even in the realm of comprehensive but only focused on games I have actually played.
Dungeon Crawl: Dungeon Crawl (or Linley's Dungeon Crawl) is easily the most popular game on this list but it still gets far less attention than the Big Three. I'm not sure why, since it's my favorite roguelike. It not only has a better graphical tileset than the Big Three but it's gameplay is just excellent.
There's a wide variety of classes (28) and races (26) to pick from and playstyles can vary starkly. To add even more variety, the deity you choose to worship (if any) has a marked effect on play. The challenge level, while tough, is consistent. The itemization and monsters are well done and there is enough variety in the levels without straying too far from the core play.
Some aspects do seem unfinished - if anyone knows the difference between a Mountain Dwarf and a Hill Dwarf be sure to tell me. I'm also not crazy about the way the skill system works. But all in all, it's a fun ride that will keep you coming back.
The wikipedia page has links to the latest official release as well as to the graphical tileset. But it does seem that most of the development action is on the Stone Soup variant, which is also linked, so I'd advise playing that.
Although most recommend a Dwarf Fighter to start, I've found that a Spriggan Venom Mage is the easiest class for the initial few levels which gives you a chance to grasp the gameplay when you're first starting out. There's not quite as many keyboard commands to learn as in some other roguelikes.The Tombs: This is not the greatest roguelike ever. It's probably the worst roguelike on this list. But yet it's still awesome. Why? The Tombs is a Flash game. That's right - I'm telling you can get some delicious roguelike action in your web browser, at work, without having to download a single thing. It's a pretty nice ride. You can choose to raise your base attributes or select special skills each time you gain a level. There is a fairly enjoyable magic system. And the graphics are right up my alley - nicer than ASCII but still very simple.On the downside the challenge level is uneven. It can be hard for the first level or two but then very easy for quite some time until you meet your first winged viper at which point it gets very hard. It then quickly turns into cruise control again until you meet another certain monster at which point it gets very hard again. This just doesn't sustain the right level of excitement.Powder: Powder is an excellent roguelike with great items, excellent challenge level and fun magic and skill systems. It's also very fast moving. Indeed, the creator states that one of his definitions of a roguelike is "Steam rolling monsters. If a critter is in your way, and weak, you shouldn't even notice it is there." I agree.I would play Powder on the PC all the time, but the great thing is I don't have to. Powder is a roguelike which is specially designed for the GBA (there's a DS version as well). Of course you do need a whole flash cart setup. I've probably played more Powder on a handheld than any commercial game.Lost Labyrinth: Lost Labyrinth has the best graphics of any game on this list (not that they're anything special). It's a quirky but fairly enjoyable game. It's definitely good for short gameplay periods (although it's not as fast paced as some other roguelikes). This game is very easy to pick up and play and has a much gentler learning curve than others on the list.I really love the character set-up. Rather then picking races or classes you pick from a very large list of skills or abilities. You can even select flaws, which have a negative impact on your character but grant you additional points to spend on skills. So my character usually has no ability to use magic, is hated by the gods, is cursed and has only a toothpick and paper bag to start off with. But, hey, if I can get past those first few levels, I'm cooking.One of the quirky things about this one is that the monster don't move. Bizarre, I know. They just sit there. However, most of the game is in narrow corridors so it works better then it sounds and there are ambushes. Another strange thing is the way you level. One of the very few things I liked about DDO was the way you leveled by completing quests. Likewise, in Lost Labyrinth, you level when you take the staircase down to the next floor, regardless of how many monsters you killed. This allows for different playstyles to be effective.There is a lot of variety to the levels in this game, much more than most roguelikes. All in all, it's a different but enjoyable experience. This is also the first game that actually made me want to spend money on a torch or lantern. You'll see why.
Castle of the Winds: This is a commercial game that is now freeware. It's nothing special but it is decently fun and polished.
Dwarf Fortress: This game is definitely the New Hotness in the gaming community. Pretty much everyone who is into roguelikes is checking this out. I'm the exception because of my ASCII-hating ways but I did manage to play a few games and I can see what all the excitement is about. The Fortress mode, where you create this insanely complex dwarven city is just fascinating. It's far from a traditional roguelike but I can see how it would be very fun, and there is a more traditional roguelike included (Adventure Mode). If you don't mind ASCII, this is the one game on this list you should be checking out immediately.Incursion : Unfortunately for me, this is another ASCII only game. However, I was interested enough to try it because it uses the D20 system. I couldn't get into it, but if you're into D&D, this might be the roguelike for you.IVAN: You call it IVAN, I call it Iter Vehemens Ad Necem, let's just call it awesome. This is my current obsession and a truly fascinating take on the roguelike experience. The thing most people fixate on with this game is that it deals with the body parts of your character and your enemies discretely. Sure, you can have your arm chopped off by a unicorn, pick that arm up, beat the unicorn to death with it, pray to your deity and be granted a new banana arm which you then transform with a scroll into a shiny new iron arm. And then you vomit just to top things off. But there's a lot more to this game then that. There is no class or race selection in IVAN. All your characters start off the same. There is also no identification game. A major part of most roguelikes is identifying just what the scrolls, potions and wands in your posession do. Not in IVAN.But it all comes together to create a very fun experience and the game has a relatively pleasant graphical tileset (your equipment even actually shows up on your character visually). The itemization is superb and the combat is challenging and fun. It's a great game, but it is flawed. I haven't put my finger on exactly how yet, but I will. I've barely scratched the roguelike surface here. Maybe sometime I'll do a post of non-fantasy setting roguelikes. Until then, I'll be trying to slay the Enner Beast on Level 5.