Anything non-realistic is usually my favorite.
Vibrant art styles are pretty good. I really love vibrant colors. Furry art and Sci-fi themed films/games usually have the most vibrant colors. This is one of several reasons why I have a love for games like Mothergunship and Robocraft.
Also, any cartoony, nonserious, lighthearted art style, like in TF2. Those art styles go very well with comedic settings. American TV shows like South Park, on channels like Comedy Central, Adult swim, etc. are known for cartoony styles because it fits well within the context.
Silhouette-centric styles are good as well because they add more uniqueness to certain characters and also make them easier to find. TF2 is well known for this, thanks to the varied shape of each playermodel.
I guess you could say I'm a complete nerd. Like, photo-realisim isnt my thing lol. It's not bad. But just not as memorable.