555 Timer Circuits

Built many a 555 timer circuit back in the day! But in modern times, I can get an ATMega328p already attached to a PC board for $2.50 and load code on it to do whatever I want, including blink a red LED.

Not only are cheap microcontrollers often an easier choice for things the NE555 might be used for, they often draw far less power as well. I personally prefer to use an even smaller and cheaper micro like the ATTiny13A. It's also worth noting that your traditional 555 timers don't like to run below 5V, for that you'll need something like an LMC555. If you're building up a parts inventory, it often makes sense to have a bunch of very cheap micros rather than special purpose parts.