Back in my running days my favorite workout was 1600-1200-800-400 cut-down with a one lap jog recovery. It was “fun” to get faster as you cut down and the goal was to always try to go sub 60 on that last 400. (1200 always seemed the hardest rep). Training for the 10k & 1/2 marathon I liked the 3 mile - 2mile - 1mile cut-down with a 1/2 mile jog recovery… Guess I like cut-downs. Haven’t found my thing on the bike just yet.
Anyways… What kind of torture are you into?
Probably some variation of SS bursts.
SS isn’t too hard so you feel like you can go forever but you’re actually going pretty fast. Then the bursts mix it up, it’s fun to get out of the saddle, it changes the muscle groups so you don’t feel as stuck in one position. Plus they add an appreciable amount of speed so you just feel like you’re flying down the road.
I like the ones with names I have a connection with.
A lot of the TrainerRoad ones are named after climbs in the Reno area (or so I’ve learned). And a few of the titles like Bald Knob give me a giggle but that’s my childish sense of humour.
A while I suggested a few names of climbs close to me like Boxley, Brasted, Bluebell and Birling. It’s rare that they come up but it makes me smile.
Love this!
Uninterrupted long intervals at sweetspot: 3×20’, 4×15’, or more TIZ: the Tray Mountain series comes to mind. Did Three Fools -1 once, & haven’t had the gumption or timing yet to try Wright Peak or its +2. I don’t go so much for the bursts as mwglow15 does, but I do like to settle in. Flat power targets so very easy to execute outside. And I feel a much better sense of accomplishment upon completing them than I do threshold or VO2.
2 minute VO2 max intervals or super long Z2 / tempo.
Everything else feels too hard (sweetspot / threshold) once the PLs start to rise 
When i was using TR regularly i used to really like over-unders like Avalanche Spire.
Over-unders… alternating between pain and more pain. I like the way you think. 