I've recently started playing Icewind Dale EE (restarted 5 or 6 times with different characters) and it is interesting how I have the roles laid out. Not sure if anyone else will find it interesting but thought I'd lay them out anyway.
Fighter, 2 handed weapon (main damage dealer, high hp damage soaker)
Paladin, sword & board defender (frontline defender, good AC, secondary healing support)
Fighter/Cleric, leader (buffs & heals)
Swashbuckler, trap finder (I intend to dual class into fighter once I have hit level 10 where he will become a frontline dual wielding striker)
Assassin, striker (I use the sneak attack option. He is my ranged damage dealer/melee sneak attacker. He managed to sneak attack a shadow and kill it in a single hit with the only magic weapon I had at the time)
Wizard, leader (currently she seems to be doing more buffs than anything, later I expect to add more control/damage options)
Some of the roles were determined before I started generating the PCs; Wulfgar is always a 2 handed weapon damage dealer. The Paladin was mainly because I recall finding a holy avenger at some point when I played the game years ago, I also wanted some extra healing if needed. Which brings us to the Fighter/Cleric; I needed a main healer but didn't want a straight cleric/specialty priest. The swashbuckler's main job was someone who can remove traps and I also want him to be a badass fighter. The assassin is just because I like the portrait of a black clad assassin, no specific role in mind when rolling but he is good at dealing damage (before EE he was a fighter/thief proficient in multiple weapons). The Wizard was because I didn't have one yet, she's a wild mage who has already wiped the party on one occasion, good times.
So there we have how I assigned roles in Icewind Dale. I did this as well when the game first came out, well before 4e roles were specified. Some of the roles were for a specific purpose (defence, healing/buffing, damage, trapfinding) others were really just because I like a picture or to cover a role not necessary in 4e (the arcane magic user).