The Collector Particle Beam is one of Mass Effect's best heavy weapons, with a great mix of precision and power. In Mass Effect 2 there are also some clear top choices for each weapon type.
Though unlocked at the VII level, unlocking the X-level gear requires the player to hit level 50, which usually requires New Game Plus. These weapons can only be bought from the Normandy or C-Sec requisitions officers, and require the player to gain a million credits before they're even unlocked.
The best gear in Mass Effect 1 across the board is the level X Spectre - Master Gear. Mass Effect 1 may have a more complicated and traditional RPG weapon system than the sequels, but that also makes its S-Tier weapons clear.
