I'll tell you mine (and date myself).
Back in the mid 70s the price of 8080As had finally dropped down to something a student could afford, at $39.95 (James Electronics). So I drove down there and bought one, along with the 8224 and 8228 support chips. I wired the chips together on a large protoboard along with 16 bytes (yes!) of TTL memory (2 16x4 chips, part number now lost to memory) and some LEDs. For programming the whole thing I built a box with some 7-segment displays and some octal thumbwheel switches I found in a surplus store. Yes, we were all doing octal back then! My first program was, yes, an LED blinky program - actually an LED counter program. It fit into 16 bytes with a whole byte or two to spare! And just like that, I was hooked.