Complex Dungeon Crawlers: Do they exist?

I've had a few suggestions in other threads about where I should be looking for a good dungeon crawler, but I need to be sure this time that I'm definitely looking in all the right places. Right, so this is a plea mainly to the community at large who almost certainly know way more about board games etc. than I do as I'm still getting up to speed with it all again. After playing Castle Ravenloft and Wrath of Arshadalon I've come to the conclusion that I'd like to perhaps give a more in-depth dungeon crawling game a blast. I'll list some of the things I'd like to see:

• Character generation
• More in-depth leveling mechanic than simply roll a 20 and voila I'm level 2 and that's it
• A more gradual challenge
• More narrative based gaming

Now I'm more than fully aware that what I'm talking about is indeed getting quite close to an all out RPG BUT, and this is the thing, surely such a game exists? Because I really can't believe for one second that I'm the only person in the world that would be interested in purchasing such a beast. So does it exist? If so what is it / are they and what do you guys recommend? Now I've been told and I've heard about 'Descent' but before I go down that road and have a look at it I was wandering if there were any others out there that might be worth the attention. Also I know of Claustrophobia, and yes I know I appear to have missed the boat on that one as it seems to be out of print. In fact would any of you game boffins know if it'll get another print run?

If you think there is a game out there that is worth my attention could you let me know why and what sort of experience you've had with it? My gaming budget is now going to shrink considerably as I'm currently out of work having been made recently redundant and I can't afford anymore miss steps on my way to dungeon crawling nirvana... so to speak. So if you've played a game what is it like? How do you rate it? What is its strengths and weaknesses? So far I've really enjoyed the random element of both Ravenloft and Wrath of Arshadalon and I've liked the exploration aspect and the co-operation and team dynamic, yet I've like the slick fast paced adversarial nature of Dwarf Kings Hold: Dead Rising. So what do you think? Peace out!