Unless I'm in a huge hurry (which I'm usually not), I prefer eating inside. I already go inside to order my food, since I really, really hate using the drive-thru...I figure staying inside for a few extra minutes to eat isn't all that bad.
(Plus it means I have to wait less time to start eating my food, especially for those places that aren't a two-minute drive from my apartment, as I don't like eating in the car even if I'm not the one driving.)
It all depends on a) how busy I am and b) if there are any seats in the joint. If I'm ridiculously busy, then I'll probably just take the food with me and eat at my desk at work, irrespective of how many seats there are. If I'm not busy, I'll eat in if there are seats available, and take out if there are not. Simple, really! :D
If I'm in a hurry, I normally take out/drive thru though I like being able to sit-in more. I'm usually with my family or friends when I go out to eat, so I like sitting down and being able to have conversation.
I honestly dont go out much. I enjoy it but it's expensive so I really can't. Home cooked meals are perfectly fine, can be healthier and are delicious. Plus then I can eat the leftovers for an easy lunch or another dinner( though I do this with resteraunt food as well)