I'm the type of person to tends to dive headfirst into a genre/theme, watching everything available, until I get sick of it and move on. I've done it with horror, vampires, and magical girls. Only time will tell what's next.
Short series > Long series
Naruto and Endless Eight have left me unable to watch more fillers. As such I tend to avoid 100+ episode series.
Anime > Manga
If I'm reading the manga it's likely because the anime didn't get to the end of the story.
Sub > Dub
I studied Japanese for two years, and I don't want to forget all of it. I'm not a native English speaker either, so having the writing to fall back on is a lot easier. Also, a lot of English dubs are just plain bad.