I would have to second that - any game with bullet drop and sniper rifles is a pain; S.T.A.L.K.E.R games are rather bad at doing that.RAKtheUndead said:Bolt-action sniper rifles in games with bullet drop. ARMA 2, Lee-Enfield - that says it all, really.
In Call of Pripyat, there is a mission where you have to kill two individuals in order to prevent their business transaction; note you have to kill BOTH of them else the mission is a failure, because the other escapes and will negotiate with someone else. One of the people MUST be a headshot kill else, he will survive, thanks to his monster armour, and escape unless you can hit him whilst he's running into the building; killing both of them in less than two seconds is hard because you have to calculate bullet drop into it aswell, albeit not that badly; its only like a 200 meter shot, but it still counts.
Hilariously enough, the easier solution is to launch and RPG at them, as the launcher has a x2.5 zoom and its an instakill on practically everything.
Bolt action rifles on games without the ability to quick-scope are also bad, especially when they cannot be steadied either; Killzone 1's sniper comes to mind, as it is about judging when to fire because the scope will line up, although that said, it is effectively a guaranteed instakill should you hit them. I'd also have to nominate the scoped weapons in Fallout New Vegas; even at higher levels, some of them still have enough drift to mess your shot and that's annoying when the Anti-Materiel Rifle's .50 calibre rounds cost at least 6 caps per round. Still, they are probably easier to use than this http://en.wikipedia.org/wiki/Lahti_L-39 - I suspect this is the largest weapon ever used as a sniper. Can you imagine using a 20mm Sniper rifle in Call of Duty or a Battlefield game?
The lack of really fast quickscope in Call of Duty Black Ops does make them rather harder to use, so all in all I would have to say sniper rifles. In practically every game, they are the hardest to use and usually need the most practice to perfect.
Edit: actually I can think of a few other monstrosities to master; rapid-fire SMGs in Call of Duty that also have bad recoil and big MGs with similar issues.