edit: I didn't realize this thread was over a year old. Oh well.
First of all, don't spend 3 hours on a coffee date--that's way too long. I spent an hour with a girl getting coffee today and I was already starting to run out of material. After 45 minutes (or even less) say "hey, I actually have to be somewhere at 2" (or whatever time) and give her some notice.
I personally only do coffee for a first date and that's it--usually girls suggest it because they think it is classy to get coffee/lattes and stuff. Yes, they are boring and generic but you can mix in some interesting questions to make it less so. Here are two things I make sure to do if I'm interested in her.
1. tease her playfully on something. Ask her job or what she studies and say that sounds boring. Ask her favorite kind of music and tease her on it. For example:
Her: "I listen to a lot of country music"
You: "are you serious? ok we could never really date then" or pretend to get up and leave and say "country music? ok well it was fun talking to you, i'll cya later."
This is a lot more playful and fun then just saying "cool me too."
2. set up or imply a second date (and NOT coffee again). Start by talking about a fun place you know. It could be a bar, museum, arcade, something outdoors, or some social event you heard about. It depends on what she might be interested in, but the point is to oversell the venue and be like "wait, you've never been there? ok, we're seriously going next week."
Make it seem like she is missing out and she will be more likely to want to go. Don't say "maybe we could get together again" because that lacks confidence. Say "ok we definitely going to xyz next week, I'll text you." This keeps her from thinking whether or not the coffee date was fun enough for a second date, now she will just look forward to the next one.
Remember, coffee dates are only like job interviews if you make them that way. If you ask and answer boring questions for 2 hours, then the experience will be boring for both of you. So mix it up and have some fun.
All best,
-jkwan