Literally, his only accomplishment is having a relatively bad wife. Other than that -
-Failed to get the Dragonballs when he first came to earth
-Failed to get the Dragonballs on Namek
-Failed to defeat Frieza, gets killed instead
-Failed to defeat the Androids (that loss against 18 was just sad)
-Failed to beat Cell after actually letting him get a powerup due to arrogance
-Got tricked into helping revive Buu all because he was having a midlife crisis
-Tried to kill Fat Buu with a suicide attack, instead Vegeta is the only one who dies
-Had to watch Goku save the day again vs Kid Buu and had to let Buu beat him up so Goku could charge his Spirit Bomb
-Got humiliated by Beerus
-Let Frieza blow up the earth because he hesitated to kill him
-Lost against Hit...badly
-Got his ass whooped by Goku Black/Merged Zamasu on multiple occasions, fails to save his future son's timeline
-Gets eliminated before Goku in the ToP
And those are just the major ones off the top of my head, there are plenty more times he took Ls against minor villains like Zarbon.
The Prince of all Ls.