Need Vonnegut Help

Looking for suggestions here.

I have a 17 year old grandson. I have a shelf full of Vonnegut. I haven't read any of them in over 20 years so I'm having trouble picking out what to send along for him when his mother comes out to visit.

What was the Vonnegut that got you hooked (if you were hooked)?

Anyone have any suggestions on what to recommend as a first Vonnegut read for a teen-aged boy in this era of instant-everything? He does like to read. I know he hasn't read any Vonnegut yet.

Thanks.