E3 2013 (Villager/Mega Man/WFT)- I tend to lump this all into one mega Smash 4 reveal trailer as that's how I saw it. I don't really have a personal attachment to either of these newcomers but it was the first time I laid eyes on the new HD Smash. The new theme was perfect pump-up music as was that Mega Man remix. Just awesome.
Robin/Lucina/Falcon- Aside from perhaps the reveal, the only trailer I audibly got giddy over. I have never played Awakening--I'm getting around to it--but at the time Gematsu was scripture. I was so excited because I feared Gematsu was the limit to the newcomers. Add Captain Falcon doing his thing and the fact it was just an entertaining trailer and it was awesome. It made Smash speculation fun again
Little Mac- The art direction of this trailer was extraordinary. I loved the bit between Samus and Mac and Doc Louis's commentary was very entertaining. The music was great too.
Greninja/Charizard- The death of the Pokemon Trainer. Charizard v. Mario was an entertaining matchup and I will admit I thought Greninja was Mewtwo for the most fleeting of moments. Greninja was my Gen VI starter and by far my favorite new pokemon of that generation. Like many others have said, he was the newcomer I never knew I wanted.
Shulk- Another very fun and entertaining trailer. The Marth/Link teamup was so sweet as was the duel between them and Shulk. Another trailer with fantastic music. I'm noticing a pattern. He also looks fun to play which is a relief to me. I don't know why but he just looked bad in the leaked video.
Mii Fighters- I'm probably not going to mess with the Mii characters much, so they don't do anything for me. This trailer is up here purely based on that Reggie-Iwata smack down. Hilarious stuff.
Pac-Man- Sakurai works his magic again. I was not looking forward to Pac-Man at all until this trailer. He looks pretty interesting and is a great retro callback. Why so low then? Every other trailer had a really cool CGI/Live-Action/Anime-Style portion with a splash that got you extremely hyped for the reveal. This trailer didn't.
Palutena- All this trailer did was make me sad there isn't a Smash anime.
Rosalina- The only newcomer so far I don't really like. The execution is pretty good on the fighter but I'm still meh overall on Rosalina as a character. Just can't get excited for her.
Sonic- SOOOONIIIICCC HEEEROOOOEEESSSS