'Traditional' Bards - like the ones you'd find in D&D - are really a mix of character concepts. They are often described as 'jack of all trades, master of none', combining a bit of magical talent and some fighting prowess with a broad array of stealth skills and the ability to influence others through their charisma. Given that description, you'd think Bards would work rather well in ES games, which really encourage mixing of skillsets.
But Bard characters have been supported rather minimally throughout the ES series. Morrowind and Oblivion had premade Bard classes, mostly involving social skills, some crafting, Illusion, and a bit of light combat and stealth skills. Skyrim of course had the Bard's College, which was fairly limited. None of these games models the Bard perfectly, but which one comes closest, and gives Bard characters an opportunity to shine on their own strengths?
My take:
Morrowind - I have the least playing experience with MW, but there seems to be a lot of inter-faction politics available here, which could be suitable for a social character. The problem is, many of these factions are very specific to certain character archetypes, none of which really fits the Bard. I guess the closest fit could be House Hlaalu and/or the Thieves' Guild? There are many opportunities for generic adventuring in MW, which works well with a wandering vagabond concept, but of course there's limited ways to make money outside of heroically (or evilly) killing stuff and looting the lairs, or performing relatively minor fetch-type quests. Still, MW gets points for having NPC disposition and Speechcraft/Mercantile as skills that get used far more often - and actively - than in Skyrim. The sense of exploration of a fascinating, strange landscape also helps.
Oblivion - OB has a great atmosphere for a Bard: it's a cheerful, bucolic landscape filled with nobles and villagers; a fairly generic (but beautiful!) medieval-type setting (as long as Oblivion gates don't start opening up all over the place). You can really imagine a Bard wandering around from town to town, plying his trade. Of course, outside of some mods there's no real way to model that experience. And there are far fewer factions than in MW. The guild quests also have the problem that they progress fairly quickly into serious, you're-saving-the-whole-guild type stuff. One approach my wife is currently taking with a Bard-ish character she's playing in a (modded) Oblivion is to join 3 guilds (MG, TG, FG) and progress through them in a minor way, not rising too high in the ranks. That way you can maintain your status as a dabbler. The mechanics of OB are ok for a Bard - they retain NPC disposition and the social skills, though the latter are arguably far less useful than in MW.
Skyrim - Apart from the rather slapdash inclusion of the Bards' College, Skyrim probably offers the least opportunities for Bard roleplaying. The College 'questline' is pretty short and consists mostly of the same kind of thing you always do in Skyrim - go into dungeon A, kill stuff, get treasure B. It's nice that there is some history and backstory attached to those quests, though. But apart from that, Skyrim overall is really dark. It is very difficult to maintain a sense of your character as a happy-go-lucky adventuring type, and I think part of this is simply due to the real lack of enemy types. If you're killing something in Skyrim, there's a really good chance it's a person. In earlier games, there were more hostile creatures. But since so many of Skyrim's locations feature human enemies, it's hard to escape the growing sense that your character is a grim badass treading an amoral world. That's great some of the time, but it's not really optimal for a Bard.
I guess if forced to rank these 3 games at this point, I'd say OB, MW, then Skyrim from best to worst in terms of Bard roleplay opportunities. But what are your thoughts?