Your 3 best investments for fitness?

I've seen a lot of posts on workout tapes, exercise games, and technology (fit bits, heart rate monitors, etc) that people are using to help them burn calories. If someone was watching their cash but looking to get a great workout, what are the 3 things you would say are worth the investment?

Mine:
1. Subscription to SELF magazine. They share all the recipes and workouts online for free, but for me getting the magazine in the mail each month gives me a little bit of renewed motivation alongside some great ideas. I tear out the workouts and recipes and keep them in their own binder so I never get bored and can take them with me on a trip.
2. Building a "home gym" with little investments over time. I don't own any big pieces of equipment but over the past 5 years I've accumulated a couple different weights in dumbbells, a jumprope, one of those blow up balls, a resistance band, yoga mat, and (my favorite) 2 kettlebells. None were very pricey one their own and allow me to try different exercises.
3. 1 month with a professional trainer. I consider the time I spent doing Crossfit INVALUABLE. I worked with people who taught me good form and technique. I learned how to motivate myself through a workout and how to listen to my body. I couldn't afford to be a continuous member, but I know my time with them has prevented a lot of potential injuries and opened my horizons on exercise.

Things that barely missed the list: A good pair of cross training shoes (I LOVE my Vibrams even though I look like a hipster) my Gymboss interval trainer (It's not a necessary piece of equipment, but it does allow me to focus on certain workouts more intensely than if I were watching a clock)

Things that I always want and then decide it's not worth the cash: Heart rate monitor. I actually bought one once and then returned it. If you put one of these on your list I'd love to hear why you feel it helps. I just don't see the point of the investment but maybe that's because I just don't really understand how to use one to my benefit. I feel I would be too distracted by the numbers than paying attention to how my body feels.