The third cover has a really awkward balance. The title doesn't stick out, the subtitle is hard to read, and the frisbee looks too small (plus, it's directly centered, looking like a middle school art project). The #2 cover is absolutely cliche, and makes me want to wash the dish rather than have a conversation. Ergo, the #1 cover gets my vote. The additional person and setting actually looks like you are sitting down to converse.
I agree that the coffee covers have been done before. However, since your book is a collective work of over 100 youth workers, and it's a book of conversations between youth workers, I think # 2 is the best option by far. The frisbee one is cool, but I just don't think it captures the whole audience. Sure, you and I like disc golf, but how many kids and youth workers across the country do? Probably not nearly as many that like coffee! Plus, the more rugged look of the table and the dripped coffee in cover #2 really captures the essence of youth ministry conversations. They require coffee :) and are not easy conversations. Make sense?