This is gonna sound funny and ironic but there is one game system I have been all to often associated with that I now would have to say is one that I can do without.
The rulesystem I speak of is D&D.
Now, some of you may know that I am one of the people who has been involved in converting Harn to d20 a few years back. I was the one calling on people to stop lambasting other systems but critque them based on their merit or lack thereof. Therefore I will say why I have grown tired of D&D and all things d20.
For starters it is amazingly complicated. It has so many rules and options that a person who only has a casual interest in RPG's like myself these days is absolutley crushed by the number of variables one must remember in order to play your character. I mean I have been playing D&D for the past 18 months at least once a week and I can tell you that my knowledge of the system is pathetic when I see how much has been written as add-on rules and such for the system. Granted the basics are pretty clear but if anyone in your group is the least bit motivated to get informed you are left in the dust by all the subtle nuances that exist when creating synergy bonuses with skills and feats and the like. Oi!
Secondly, the character advancement is exponential. Feats stack on feats, attacks stack on attacks and after 7th or 8th level your character does not resemble the person they were 18-21 sessions ago. Granted, unlike Harnmaster which provides for very little character advancement as far as skills and stats go (the average character in Harnmaster will have improved no more than 15% in a skill over the same period if they were lucky with rolls and used that skill incessantly), you definately see development of your character but it is all about the numbers and less and less about the actual character.
Thirdly, it tries to be all things to everyone and fails. Unlike Savage Worlds, which manages to tie roleplaying and miniature gaming together brilliantly, D&D can't do either very well. Skill development is stilted in most character classes due to low skill points and combat is requires extensive moderation and knowledge that it is a slow and laboured affair. Systems like Ars Magica and even Harnmaster to a certain extent are much less focussed on tactics and more on general strategy and prior development. This ensures that you stay "in the game" while combats occur and there is no need to change pace due to additional rules. Although in theory Skill and Combat are essentially the same (roll to beat target level) the addition of various feats and such make them two very different affairs in practice.
Finally, I have to agree with most people who posted that the magic level in default D&D is too high. But more to the point, there is no in game consequences to magic use and as a result it is abused and leads to a cavalier approach. The careless nature of the magic system (fire and forget) plus the lack of consequences make it little better than another weapon in the arsenal or armour from the armory. I actually think most game systems suffer from this fate and Harnmaster has the potential to follow this path except for fatigue and the way that societal pressure play a part in the game (if not represented in the rules).
Now, D&D is popular, it is very well represented in most centres where gaming occurs and it allowed me to get into gaming again after being without for quite awhile so there is a definate value to it and I will treasure the friendships I made playing it. And if there were a way to run a campaign that ran for a year ended satisfactorially by level 6 or 7 than I would see it in another light. But the reality is it is an unsustainable system that becomes more and more ridiculous as it progresses.
That is it. Rant over. Now Nick can sit back and say I told you so

. But if I never play another game of D&D I'll be happy.
Oh and by the way I dislike Rolemaster for most of the same reasons I mentioned about D&D except it actually has a much more gradual advancement (the benefit of percentile vs. d20's). I haven't seen HARP but from what I have seen of the descriptions it appears that ICE is going the wrong direction IMHO.