Brainstorming, thanks to Dan John…

A "three-way" split idea. Not a three-day split, mind you, since proper rest might require three days between workouts, etc. Listen to your body, not a calendar. Rest between workouts until adequately recovered.

%s mentioned below are based on 1RM (known or estimated). EXERCISE : WEIGHT x REPS

Warmups much as Dan John describes them in the first paragraph here.

I came up with the following pretty much off the top of my head, based on what I think are the best "all-around", "essential" strength and conditioning movements for the moderately seriously "fitness-minded" person.

Core principles include: "K.I.S.S.", "Less is more", "It's all about Push-Pull", "specificity", and "double progression".

KEY POINT: These are not circuits, though circuits are my wont. As such, each set would provide enough intensity to make gains but also require a limited enough volume, not haunted by the specter of numerous follow-up, accessory exercises, as to allow for maximal focus and effort each time around. Note that he first two sets on Monday are basically just warmup sets, so its effectively a "one-set" workout, despite its formally triplicate structure. As Clarence Bass puts it:

Monday: 30% x 15, 70% x 8, 90% x 3 (or failure) 
SQ - PUSH
BP - PUSH
DL - PULL

Wednesday: 30% x 5, 40% x 5, 50% x 5, 60% x 5, 70% x 5
Overhead Squat - PUSH
CJ - PULL-PUSH
SDL - PULL

Friday: 30% x 12, 50% x 12, 70% x 6 (or failure) 
FSQ - PUSH 
IBP - PUSH
weighted PU - PULL

Purely guesstimating, for me this would look roughly like so:

Monday: 30% x 15, 70% x 8, 90% x 3 (or failure) 
SQ - 50 x 15, 90 x 8, 125 x 3 
BP - 35 x 15, 70 x 8, 95 x 3
DL - 50 x 15, 105 x 8, 135 x 3

Wednesday: 30% x 5, 40% x 5, 50% x 5, 60% x 5, 70% x 5
OSQ - 30 x 5, 40 x 5, 45 x 5, 55 x 5, 65 x 5
CJ - 25 x 5, 30 x 5, 35 x 5, 42 x 5, 50 x 5 
SDL - 45 x 5, 55 x 5, 70 x 5, 85 x 5, 100 x 5

Friday: 30% x 12, 50% x 12, 70% x 6 (or failure) 
FSQ - 35 x 12, 55 x 12, 80 x 6
IBP - 30 x 12, 45 x 12, 65 x 6 
weighted PU - bdw + 5 x 12, bdw + 7.5 x 12, bdw + 10 x 6 

If you bothered to parse all that, it would actually be three uniquely grueling workouts, all under 45 minutes, I wager. The extra time can be filled with focused stretching, aerobic work, or hobby movements.

Monday would build power.

Wednesday would build stamina, speed, core, neuromuscular coordination, mental focus, and better technique.

Friday would augment both Monday and Wednesday, without demanding too much after two such arduous workouts.

Off-days could be given to focused abcore training, grip training, yoga, swimming, sprinting, walking, track and field drills, Tabata sessions, whatever.  (Incidentally, I think the best exercises for the Tabata method are thrusters, burpees, jumping pullups, and what I call jumpie-pullups [viz. start in a deep knee bend position, jump up into a pullups, descend into knee bend squat, repeat].)

I'm really eager to try this out.

I've been told the 5 x 5 is best for beginners and serious powerlifters, though even that latter benefit has been contested by a muscle-head friend of mine, so my goal is to complete at least a month of the Quick Mass regimen, then switch back to my Even Keel regimen for six weeks, and then try the above, if my gym is suitable for Olympic lifts.