Find out what they like and give accordingly. My local parish priest is a bit of a cricket fan. Last year several members of the choir chipped in and gave him tickets to a couple of cricket matches.
For those people you don’t really know, don’t have a lot of connections to, I wouldn’t think a gift was necessary. Perhaps some baked goods - it’s personal but not extravagant.
I agree with Mr. Goob. There’s a book called All I Need to Know about Ministry I Learned from Fly Fishing by Myrlene L J Hamilton that made a pretty good gift for a minister I know that likes to fish.
I agree with the book idea, myself. There’s a great book out there called RealLivePreacher.com (check out the website of the same name) that has some really amazing essays about the perks and pitfalls of the ministry and life in general. While the majority of those essays can be found directly on the site, having the book in hand is nice. I gave my copy to my preacher back home around Christmas-time last year - it’s easy reading that packs a huge emotional punch.