The types that I can or want to answer? :P Well, that is so general. xD
I like questions that contain a new topic, a challenge or something fun; "some" intellectual, philosophycal or hypothetical questions are nice too. Also, I answer some questions which I think I actually "can" give it a good advice.
related to religions and cultures, related to social issues, related to race. because these are in my area of knowledge and related to what I study. I also like some questions related to philosophy, and Some funny ones, but if they make sense.
I think the ones where 99.9% of people on GAG all have something to share are best. Recent ones have been Willow4's question about sharing pictures of us as kids/babies, and AnimeDreama's "introduce yourself".
Questions that make sense lol jk questions about sex and relationships
Any question that makes me sit and think about my answer. Sometimes it's really easy to spit it out, my fingers can't keep up. But sometimes, a question REALLY puzzles me and I like to sit and think about the answer... I enjoy that, because it makes me look at myself or my life/situation, etc.