As a Veigar main, I usually use either Final Boss Veigar or Bad Santa Veigar (thank you hextech crafting). It's mainly because his spells on his classic skin don't have that nice impact to them. There's a nice thump/crunch sound when you land a Q as Bad Santa Veigar, and the effect that tells you your last hit was successful as Final Boss Veigar has a clear sound effect and +Magic icon.
But honestly, he could use a VU. I don't think his model has changed much at all since his release, and it really shows. When you look at his new skins, you can really see the difference. Have you seen the textures on his Event Horizon? It looks really old and doesn't fit into the Summoner's Rift VU from last season.
Not to mention his ult isn't nearly as impressive as it should be in his classic skin, imo. For Bad Santa, it's an exploding gift that has some neat little particle effects. For Final Boss Veigar, it's a massive explosion, where the fabric of the game itself seems to open up and erupt beneath them. But classic? Nah, just throw some extra sparkles on his Q. Bitches love sparkles.
