This took some real consideration and in the end I decided to go with coasters that were in someway 'offensive' to me, rather than coasters that I think are just boring / poorly designed. I came up with this list in the end, in no particular order;
El Condor (Walibi Holland) - Was a toss up between this and Limit as only wanted to include 1 SLC but Limit seemed to have improved slightly on my second visit to Heide. Tbh, most SLC's could occupy this spot
I remember El Condor being particuarly rough, and will always remember having to get on with the loading platform randomly going up and down lol.
Shockwave (Kings Dominion) - Togo stand up that has now been removed, this was a very unpleasant ride and the restraints were just hilariously bad!
Sequoia Adventure (Gardaland) - What were they smoking?!? Why, just why!
G-Force (Drayton Manor) - Really hate the inverted lift thing, the queue is horrendous and throughputs laughable. The actual ride itself off the lift isn't TOO offensive I guess....
Soarin' Eagle (Screamzone / Luna Park) - Zamperla Volare, enough said I think
Tornado (Bakken) - Possibly the most aggressive / violent ride that I've ever experienced, I found this deeply unpleasant!
Furious Baco (Port Aventura) - Great if you need your spine rearranging! Launch is good but what follows is a mediocre layout fraught with pain.
Nighthawk (Carowinds) - Vekoma Flying Dutchman that is massively rudimentary compared to it's B&M counterparts, with all the Vekoma roughness to go with it! Saying that, laying on your back whilst stuck on the brake run is surprisingly comfy!
Hurler (Kings Dominion) - Incredibly rough woody that literally rattles your teeth out on that first turn
Mean Streak (Cedar Point) - Whilst not particuarly rough compared to some of the woodies I've ridden, it's by no means comfortable and earns it's place here mainly due to lost potential. It's so damn huge but just seems to do so little with it, I just feel it could have been so much more (similar to how I feel about PMBO). Would love to see RMC do something with this coaster
If I was to include coasters I could fall asleep on, then Cagliostro, Temple of the Nighthawk, Dizz and Superdooperlooper would be right up there!