I run hills regularly (obviously) since I run trails and not rail trails plus it's hilly around here. I guess the biggest climbs I get in my immediate area top off about five or six hundred feet in one climb, typically over a mile or less, though sometime longer. Usually very steep in sections. I've noticed when going up big hills often there are tricky steep sections and then things ease up before you get slammed again. I often break up hill climbs that way. Into little sections. I guess some of my favorite hills currently are over at Coventry Woods. There is one hill, on rock run trail, that is maybe just 200-250 feet and not super steep or rocky. You can run it fast downhill, and even surge uphill on it if you want to do some work. It tops off on a ridgeline where you get flat running for a mile, and bottoms out by a little spring/creek fed pond. The Lady takes a water break there.
Some of my 100 mile races have had tremendous amounts of climbing (12,000-20,000 feet) but I think on a per mile basis the Hyner Challenge 25k had the most bang for the buck. Over 4,200 feet of climbing over 16 miles which averages out to over 250 feet per mile, though of course the uphills came in sections and there was downhill too. They name several of the hills on that course... Humble Hill and SOB. SOB was the end of a big long climb and was so steep I crab crawled up it. It was actually pretty fun.
Run/workout: 7 miles last night on the least hilly of all my trail routes at Green Lane. Still gray damp and misty, and the trails were wet, mucky, and squishy. There is a very fun section of trail on this route with several little hills (30-50 feet max) and it's a fun section to surge through as it's right next to the lake and you can really accelerate up/down those hills. Not so much last night though because of the muck. Probably 6 or 7 tonight as well on a trail TBD.
Bonus: I often look forward to big hills during an ultra so that I can take a walk break.