Here is the full list of all 11 Mass Effect: Legendary Edition trophies - there are 5 bronze, 5 silver and 1 gold.
Kill 100 enemies with melee attacks in Mass Effect 1, 2 or 3
Finish Mass Effect 1, 2 and 3 with the same character
Complete all three games in Mass Effect Legendary Edition on Insanity without changing difficulty
Complete two games in Mass Effect Legendary Edition on Insanity without changing difficulty
Kill 2,000 enemies in Mass Effect 1, 2 or 3
Establish or rekindle a romantic relationship in all three games in Mass Effect Legendary Edition
Kill 1,000 enemies in Mass Effect 1, 2 or 3
Establish or rekindle a romantic relationship in two games in Mass Effect Legendary Edition
Complete Mass Effect 1, 2 or 3 on Insanity without changing difficulty
Establish a romantic relationship in Mass Effect 1, 2 or 3
Kill 250 enemies in Mass Effect 1, 2 or 3