These are a few of my favorite things

Raindrops on roses and whiskers on kittens
Bright copper kettles and warm woolen mittens
Brown paper packages tied up with strings
These are a few of my favorite things

GymBoss Timer:

For the money this is a cool toy. Doing intervals from a watch is awkward, a stopwatch has its use but not for this, egg timers have a use too, but, nothing is as handy for intervals as a Gymboss. For the cost you could get several and program each with different work/rest cycles. Kinda of like a treadmill the Gymboss is merciless and you just have to keep up. That said, if you are tight on money, we've found that taking 6 deep steady breaths equals about 30 seconds. If you don't cheat on the rest the work generally takes care of itself. But, the GymBoss is still, well... "Boss Man!"

Bumper Plates:

I think that dropping weights is fashionable because CrossFit and BodyTribe have made it so. And I think that is regrettable -- and given that some of the folks I've seen doing it, do so for the wrong reasons, sloppy and lazy -- and annoying. That said, bumper plates can be the difference in confidence that it takes to make a max, or near max effort. They help with confidence to try new stuff when the possibility of dropping it exists. I like the freedom bumper plates create in changing your work out space, no longer are you bound to the lifting platform. Grab the bar and a couple plates and head out for adventure.

Dumbbells:

We used dumbbells a lot this summer and I've come to love them for their versatility. Kettle-bells are all the rage just now. But, they are expensive and many gyms don't have them. In the end I like the symmetry and balance that dumbbells offer over kettle-bells. To date, I can't think of anything that can be done with kettle-bells that can't be done with dumbbells. Some folks honk off about the toughening effect of getting hit by the kettle-bell as it flops over your grip. Meh. If you need toughening just go spar don't expect your kettle-bell to do it. All of that said, I don't really need to get into it with Kettle-bell aficionados, so if you love kettle-bells more power to you, I'm just saying for me. As with bumper plates I love that we are breaking down the walls of the gym and taking the gear off to adventure.

Weighted Vest:

I love my vest. It hasn't made me faster, nor has it made me jump higher, but, no other single piece of equipment has improved my work capacity so substantially and so quickly. It also helps with developing heat tolerance as it traps the heat. I think a 20lb vest is adequate for the vast majority of us. If I were a first responder, or in the military, I'd work myself up to 40lbs. I don't like how expensive they are particularly with relation to how cheaply they are constructed. So, I'd suggest buying the best quality you can afford even if it is a stretch. Or, consider making your own. I encountered a company that makes a vest with capacity up to 60lbs, they sell only the vest so you have to get the weights locally. Saves on shipping and allows you lots of room to customize the load and the workout. If I remember correctly plain old 5lb and 2.5lb plates.

Sandbag:

Make yourself a sandbag. Actually, make yourself a couple in different weights. I have a 45lb bag and I love it. Cheap and easy tools to make for yourself. I've done clean and jerks, get ups, hill carries, sprints, thrusters, rows, good-mornings, diagonal raises, blah, blah, blah. Really these are limited only by your imagination.

Zone Eating:

Really the only system that has allowed me to change my body composition with any kind of finesse. Too, it gives me the tools to effect my blood cholesterol unlike any other eating plan I've encountered. I wish I'd started with adjusting my eating plan rather than following the popular idiocy about more slogging on the ergs. You are what you eat. And if you want to lose fat and keep it off you have to change what and how much you eat. I can burn at best 1000 calories in a really hard hour, I can eat 1000 calories in about 5 minutes. If I'm not in control of my eating there is just no way to stay ahead of it with exercise.