The first time, I believe I chose Piplup, making him my very first Pokemon. For SS (which I got as a Christmas gift last year) my sister's fiance helped me find the evolutions of the starters and eventually led me to choose Cyndaquil.
I remember soft-resetting for hours to find a shiny starter on HG. Took me about half of an hour to get a shiny Chikorita. After, I spent 3ish hours soft-resetting some more and couldn't find a thing.