Soap box is out...
I hate D&D 4.0 with a passion (sorry to the supporters). IMO, it's everything wrong with RPG design and MMO's all rolled into one. Combat was over-emphasized and skills were almost completely made obsolete. It's an abomination on an epic scale.
I'm a very old school RPG player. Back when it was more about ROLE-playing and not about ROLL-playing (magic item SLOTS???? Really guys??? Please help me understand how my character only has one neck slot. Because I REALLY don't understand how that makes any fucking sense at all. Look... I just put on two necklaces. I could probably wear 15 of them without any issues.).
Putting soap box away now...
Systems I've played and liked include the following.
Runequest (3rd edition) - several games used this basic system including another personal favorite Stormbringer (truly a bad game but with a great mythos). It is entirely skill based (no class system at all), and that makes for a very customizable character. It's also very lethal, so even an experienced PC can be killed by an orc. A lot of people shy away from non-heroic systems because they don't like having their guys die in un-heroic ways (wayward arrow from an orc). But I'm personally a fan (I like rolling up new characters anyway, so I don't tend to get attached).
Warhammer Fantasy RP (1st edition and 3rd edition) - 1st edition was bare bones, but the setting is dark and really gritty. 3rd edition is less gritty but it has a wonderful RP system that is well designed. All the emphasis on cards and tokens takes away from some of it, but there are great ideas in this game (party identity and tension, stress and fatigue management, career development, heavy focus on non-combat skills and situations). It's a lovely system even if it has flaws.
Hackmaster (most recent edition) - a really well thought out game that feels like AD&D but has a lot of really unique and tight mechanics to address things that don't work in D&D (threshold of pain, tracking combat using seconds instead of turns, realistic armor system not based on abstract AC value). It's not without it's weaknesses (too crunchy at times - I suggest you do some unarmed combat and let me know how long that takes you to resolve), but this is a solid game.
D&D (AD&D through 4.0) - 3.5 is my favorite system because of it's elegance. But it breaks down at around 10 or 11th level. Combat takes a billion years yet it's outcome is generally known ahead of time due to the inevitability of the escalating HP system. Anything capable of killing you WILL kill you pretty much every time. And everything else is going to die before that happens - again EVERY SINGLE TIME. Barring a ridiculous string of lucky or unlucky rolls, nothing in this game is ever surprising, and that really takes a lot of the tension out of the game for me at least.
