The classic bitching and whining about most HNM's (and a lot of NM's) is the un-natural method in which cheating morons warp-claim/packet sniff/whateverthefuckcheatofchoice/JPONRYbutton a big monster.
I say, take the claim process on these monsters out of the hands of players entirely. Make these big guys do it Soviet style. They pick YOU.
They claim YOU. NM/HNM is given widescan of a size appropriate to the monster. When it spawns, it automatically picks a character in it's range, generates a significant amount of hate towards them, and aggros immediately...spawning "claimed" towards that player and his/her party.
Do this for every single NM/HNM it matters for in the game. If there's nobody there when it spawns, the monster aggros on the first person it can detect inside it's scan range and goes to town when-ever that event occurs. Since it's server side, nobody's hacking the claim method. Ulli pops, he looks around, picks someone to be pissed at, and tools on them and their friends. Serket wakes up in the basement, he picks on someone. Mee Deggi spawns, nobody's near and someone wanders close enough- off he goes on them. (I know, a yaright there. When is his spawn area ever uncamped?)
Make sure the monster has a nice broad range- Argus's scan checks the entire room he's in when he spawns. Something like King Behemoth would be far broader. Ulli as well.
End of cheating for claims. If you're in the area and not stealthed to the monster's detection methods, you and your PT get the chance if the monster spawns when you're around. Yeah, this may mean the first thing your NM does is jump the healer until you can peel it off. Be prepared.
What do people think of the concept?