biotic amp, asari sword, other?

Remnant cryo-gauntlet.

You'll LOVE it.

Agreed.

lynx7386 , I prefer the Biotic Amp, as well. I switched to the cryo-gauntlet, though, because it's similar, plus it's an Ultra Rare weapon. This means you'll get 4/5 augmentation slots, rather than 2/3. Those slots are huge, since melee weapons are "always equipped". Those are two extra buffs built into your melee weapon.

The cryo-gauntlet is also just fun. It does okay damage, but it snap freezes unprotected targets in one hit. It does fairly well against protected targets, also. You can either finish the frozen target, or use them to setup a small combo detonation.

The Kett Carfalon is useful on Vanguard because it siphons health with its attacks.  So with each melee attack on Vanguard you'll be regaining health and shields.  But the attack is a bit clumsy like the Asari Sword.

For regular melee I prefer the omni-blade...it's quick and straight-forward with no weird movements/animations.

Vanguad you said?

1)AF ---> ( prime )
2)Lance(shield drain) ---> ( make a big boom multiple times for glorious explosions )
3)charge for shield recharge
4)Repeat

You won't have enough time to melee with this build
BUT if you do want to melee anyway

1)Hammer if you're badass
2)A. sword if you're samurai
3)Cryo if you're a troll

The krogan hammer would probably look ridiculous on Sara, lol.

My current ability setup is charge, nova, and tactical cloak.

For me, it'd be the Asari sword, though I'd go with a crafted sword modded to my taste. Big fan of the teleport.

Exactly my feelings. I tried the Electric Firaan first, and hated its short reach and underhanded grip. It makes no sense for Ryder to wield the knife that way. The cryo-gauntlet is great. It has better reach and better damage. It also puts common enemies on the ground for a looong time, if you let them survive the initial attack sequence for some reason.

I stuck with the gauntlet because I didn't have enough Heleus research points to try the vakarsh. I'm planning on using that in my next playthrough (unless it's terrible, in which case I'll go back to the gauntlet).

asari sword is so bad because of the teleport for me,specially on vanguard that uses charge. With charge i'm already on the enemy
carfalon kett would be the best for me,with its lifesteal but i don't like the slow animation
angaran's weapons are very fast but have low damage,so i choose biotic amp. fast enough and average damage

i liked also cryo gauntlet but i couldn't make it work for freezing combos

The electric firaan stuns. Typo, I assume, but for future readers I figured I'd point it out. (I don't recall the Biotic Amp stunning, at least. It's possible I could've overlooked a short stun, I guess.)

Remnant Cryo Gauntlet, it's the only one that does something usefull besides damage.

I nkind of like all the melee weapons. Last character was into the cryo gauntlet. Right now I favour the carfalon. I have used the omni blade the least though.