We like capacitors so much we made a kids' show about them.   They're super handy and it's really helpful to have a variety lying around to pick and choose from.

This is a 10 pack of 220uF 16v capacitors so they can be used with any DC voltage up to 16V.  They have a tolerance of ±20% and long flexible pins that make them great for perf or breadboards. Remember that electrolytic capacitors are good for low-frequency filtering (~1KHz or less), for higher frequency, pair up with a ceramic capacitor.

We use these capacitors in our own kits, and they're of great quality.  They're so useful we're selling them in packs of 10.  Each has nice clear labeling on the body as well in case you have a capacitor mix-up.