Kingdom Hearts (Casual)(My favorites are KH1 and KH2, while my not surprisingly least favorite is Chain of Memories)
Smash Bros (although I really dislike Smash 4 [please don't hurt me])(Die-hard casual)(I love Brawl. Melee and 64 are on the same tier below it.)
Mario Kart (Wii and Double Dash are my favorites. I kinda like 8 just the same, but it's missing something magical to me that those two seem to lack)
Super Mario (Sunshine is my top favorite)
Puyo Puyo
Guitar Hero (I really have only played 3: Legends of Rock and Live)
Theathrhythm
Rhythm Heaven
Yokai Watch
Mario & Sonic Olympics (I mostly like the first one in the Beijing 2008 Olympics, the Sochi 2014 Winter Olympics and the Rio 2016 Olympics)
Animal Crossing
(New Leaf isn't my favorite [don't hurt me]. That would ironically go for the first one I played, City Folk. I also like the rest of the, actually all more than New Leaf [puts up shield out of fear])
Dragon Quest (I love 7 and 8)
Wario Ware
Fortune Street
Donkey Kong Country (I started with Returns and that's my favorite. I'm not very familiar with the older games and never finished Tropical Freeze, but I like the series)
Pokemon (only interested in older gens before Kalos region)
Art Academy (although that series is pretty much dead now)
Wii series games (I love Wii Sports, Fit, Sports Resort, Music, Party and Wii Play including their sequels)
MySims (although that series is pretty much dead now)
Zelda (not all that interested, but I like games like Wind Waker, Ocarina of Time and Majora's Mask)
NES Remix
F-Zero (only the first one)
Pilotwings
Pikmin (I like them all, including Hey! Pikmin)
Brain Age
Sonic (and if you wonder, yes I like Sonic 06, Sonic Black Knight, Sonic and the Secret Rings and Shadow the Hedgehog)
Luigi's Mansion
GTA (The 3D universe games are my favorites)
Kirby
My ideas on retro games are hit or miss. I don't really have any specific preferences on retro games. Generally though, things like story, stability and how well things like controls have aged compared to games in the series or same genre in the modern day may influence my opinion about them.