Well I don't have a lot of different rods for certain applications, but I do have a few.

Cranking- The trend is to have a more flexible rod for absorbing the strike, like fiberglass. I use such a rod. 6'6'' to 7" Med action Daiwa heartland. I also have a Quantum graphite version. I broke my 7' Castaway Cranking Stick (in my Jeep door)a few years ago. That rod was sweet. Same rod for lipless cranks.

Spinnerbaits- Some like the same style of rod for spinnerbaits, but not me. I like a stiffer rod 6' to 6'6". Allows my casts to be more accurate, and your trying to set a thicker hook into the fish. Spinnerbait hooks are usually a little thicker than most crankbait ones. Plus there is usually only 1 and a trailer.

Actually I'll use this same type of rod (stiffer 6- 6'6") for most of my other baitcasting applications: Topwater, tubes, jigs, worms. Especially when using a "walking the dog" technique. The bait is more responsive than on a limber rod.

On my spinning rods, I like light, but stiff rods, especially when dropshotting or splitshotting. The stiff rod aids in feeling the bite. A light. balanced rod keeps fatigue down over a long day, and hook sets are better. I don't have any limber spinning rods. Some use them to throw
small, light crankbaits.

Flipping- Pretty easy. Long and strong...What more do you want? Light would be good, but it's hard to come by with a long heavy stick. Balanced would make up for that.    

I've used the same stiff 6'6" rod for jerks in the past, but have recently been trying a little lighter 6 footer. I dont hit the boat as often when twitching, but loose casting distance. Undecided yet.

What and Why do you use certain rods?
1 What rod and characteristics make it a good rod??

Dropshot?
Dragging?
Spinnerbait?
Crankbait?
Jerkbait?
Rev rig?
Flippin?
Pitchin?
Skippin?

Tell us what you like and why.......thanks