How your character looks affects your enjoyment of an MMO. This is almost a tautology; you spent time in the character creator, obviously, so you have some investment. But I think it goes beyond even that. Some of our playstyle choices come down as much to what looks cool and feels neat from a visual standpoint as it does with any other considerations. Give the exact same mechanics to a different set of visuals and people will often feel differently, even if the actual play is the same; witness the number of people in World of Warcraft with strong feelings about which Hunter spec got a gun and which one got a bow, even when the mechanics are functionally identical.
Every game has certain choices that look particularly cool – enormous capital ships in EVE Online, Red Mages in Final Fantasy XIV, several Elite specs in Guild Wars 2. There’s an obvious effort to make these things look cool, first and foremost, often to the point of enticing people who otherwise might not play with these particular options. So what about you, dear readers? How much do aesthetics impact your playstyle choices in an MMO?