Sled (or car) pushing, sled/tire dragging, high rep kettlebell/"Romanian Core Blaster" swings (and kettlebell snatches if you have the required technique), pounding a sledgehammer on an old tire, lifting and tossing a moderately heavy rock repeatedly for high reps, possibly running up hills and walking down slowly, possibly running up long flights of stairs and walking down, etc., etc.  Or, as Hapy noted, play games like hockey, soccer, squash, basketball, etc. 

Plyos, jumping, etc. are not "conditioning exercises" but are done to develop power and explosiveness.  As such, you should not do these to exhaustion or even really feel tired when doing them, as this would not result in the desired adaptation. 

 use your imagination in the gym, i have gotten into medly's! i'll do a 100ft. farmers walk, go right into a 150lb. rock lift and drop [5-8 reps] and then a dumbell snatch [changing hands ea.set] do 3-4 sets with a couple 3 minutes tween sets. you can come up with any trio you want, its quite a break from traditional training now and then, and it'll tear ya up!