I'm not a fan of rogue-likes, they have a number of things going against them for me. #1 They are unbalanced and/or have random spikes in difficulty or impossible odds #2 Extremely random proving difficult to form strategies #3 Graphics are usually similar to ones you would see in 1990's (I dont mind this so much if they played well, usually they dont and this compounds making it more obvious) #4 Little to no reward for leveling up other than you might survive slightly longer or eventually become too powerful to be stopped (Alternatively become very powerful against melee and still get one shotted by magic or something along those lines just an example) #5 Perma deaths are very common and can be frustrating (credit to lhughes41 for reminding me of this one) I understand a lot of people enjoy these types of games, I just havnt found one for me. I want to like them cause its right up my alley as far as unique experiences in the game, but its difficult.
The great strength -- and weakness -- of rogue-likes is permadeath. You care about your character and risks are to be weighed. But somewhere else in this forum there is a good discussion about alternative ways to make death important but not too punative (the weakness of rogue-like). Secondary strength is of course the random novelty of each play.
There's a nice little online game (whose name I've forgotten ) that lets you keep one item when you die, which can happen pretty often. Just that simple little touch seems to make it all worthwhile, it's weird. Sure, you have to start again, but you have those epic boots of speed and strength, that will let you carve through the start, and hopefully you'll be patient enough to survive just a bit longer... and get a even better item for your next run-through... Random insta-perma-deaths are annoying though (although can be hilarious), and I think it discourages a little bit. That depends on the depth of the game though- I played D2 on hardcore all the time, because that was non-stressful hacking and slashing. A high level guy dying sucked for sure, but it was probably your fault for being careless/ dumb, and the starting areas were pretty fun to run through.
