Some 5-man dungeons can be challenged - and beaten - with parties smaller than 5 players.
Even better, veterans have been known to fight the final boss of a raid dungeon single-handedly when the rest of their teammates have fallen!
Beating a particularly grueling dungeon with no prior knowledge of the boss fights. Getting everyone in the party to cooperate and managing to take down the final boss after the nth time will make you breathe a sigh of relief.
Beating a solo boss can be very satisfying, expecially once you get the dodging/blocking pattern down it can have a pretty good Dark Souls feel to it.
