Outstanding thread idea.
I spent the better part of 2016 recovering from ACL surgery, so things are a little screwy. That said, here we go.
1: The prowler. Oh my god why didn't I get one sooner? It's the perfect conditioning tool. Very little set-up for maximal benefit. You can push it, drag it, go high handles, low handles, sprint, walk, etc. It was a huge part of my ACL rehab, and I actually pushed the damn thing for over a mile (unloaded) as I was getting ready to get back into full on training. It was also great for getting strength back in the leg and blood flowing. I use it at least once a week now. Everyone, regardless of goals, needs to get one of these.
2: The axle. I had owned one for a while, but just didn't commit to it. As a reward to myself for staying diligent in my rehab, I treated myself to the Ironmind Apollon's axle, and because it was so damn pretty, I decided to use it a lot. I am now at the point that I use it for every training session; I bench with it, press with it, deadlift with it, and just recently started front squatting with it. Also use it for curls and continentals. Since the axle is super stiff, it makes deadlifting a real challenge, as it's tough to break off the floor and it won't whip to break through sticking points with hitching. It's also a grip challenge with assistance work, while the larger circumference means the joints take less of a pounding. My wrist and elbows feel amazing. I never use my texas power bar anymore, and if I could do it all over, I'd rather have 2 axles than an axle and a power bar.
3: Nutrition. As I get older, I keep finding this more and more important. The better I eat, the better I perform. Who woulda thought.