I really really like plyo's for lower body.
This is what I was doing awhile back: (adapted from the Feb 2004 Oxygen)
Get a Step from the aerobics room and put 7 risers under each side. This brings the step to just under knee level. I do high step ups, one legged lunges (back leg raised), box jumps, and toe taps. This lasts about 40 min, and I am drenched afterward.
I did my own thing, and changed order & exercises every week. An example:
Toe Taps 3x50 (so 25 on each side)
Backward Lunges (back foot elevated) 3x10 on each side
Step Ups 3x10 (on each side)
Toe Taps 2x50 (25 each side)
Backward Lunges (back foot elevated) 2x10 on each side
Step Ups 2x10 (on each side)
In between each set I do a set of unweighted walking lunges, unweighted Plie Squats (toes turned out) or Crunches/Abs on the ball.
So basically no rests, unless I really feel like I need it. IF I do rest, it is usually for about 1 min, give or take.
Here are some more thoughts/explanations:
Steps Ups - you said you are doing them. How high is the step? Make sure it is about knee height. Step up alternating legs, step up with one side at a time, then switch, step up sideways.....
Step Jumps - squat down in front of the step (around knee height) and explode off the ground and and on the step, still in a squat position.
Walking Lunges - do walking lunges all day long. You can do them with weight or without.
Stationary Lunges - again, with weight or without. You can switch sides, or work one side first, then repeat on other side.
Reverse Lunges - you say you are doing them, but how? Keep your back foot raised on the step behind you, then lunge down over the front leg.
Squats - do with dumbbells or a barbell if you have it.
Running Stairs - bleachers at a HS or College Stadium works perfect. If you like somewhere "historic" they often have monuments with a ton of stairs (Philly like in Rocky, DC monuments, NY museums, Santa Monica Stairs outside, etc.) Worst case scenerio, find a really big building or hotel and run their staircases, lol.
***With all the weighted exercises, when you push up to standing position, push up through the HEEL ONLY. Do NOT push up through the toe. REALLY concentrate on pushing up through the HEEL to get max work out of your butt.
Hope this helps.