>>719816963
For me? It's gotta be the NXE Dashboard

>>719818546
When you unlock an Xbox Achievement, it gives you a certain amount of points called "Gamerscore". So it would usually be like
>Achievement Unlocked (15g) - Press X to Start
or
>(100g) - Complete the Game on Hard

Back then you got cool shit for unlocking certain achievements, like gear for your Avatar or armor in Halo 3