Here are my thoughts:
Not a noob: survived first night
Boss defeated: killed your first boss
Wot m8: died for the first time
Hey look we're not lonely anymore: obtained 4 NPC's
All hell brakes loose: hard mode
Scary skeletons: defeated skeletron
Feel my power: killed 5 bosses
Can't touch this: killed the guardian
Hey look everythings red: first blood moon
Buddie's! : first pet
SPAAAAACCCEEEE: went up to space
Welcome to hell: go to hell for the first time
Cheater: spawn in any dev armour and wear it
No, you fear me now: obtain the nights edge
Am I King Arthur?
btain the Excalibur
GOTTA GO FAST: get Hermes boots or flurry boots
I have many more ideas but I think I should stop lel