Melees
Terrarian - My favorite weapon in general that I've used so far b/c of the range of the yoyo.
Meowmere - Does an amazing job against multiple monsters(events) because of the spam/speed that it gives.
Vampire Knives - It heals you back!
Magic
Shadowbeam Staff - It's good for aiming multiple monsters.
Toxic Flask - Good for close combat attacks.
Last Prism - It gives really high damaged hits if you use the right modifier.
Guns
Minishark/Megashark - The only gun that I really enjoyed in post-hardmode. I usually use it with meteor bullets.
Bows
I don't have any particular favorite bows as long as they're shot with Unholy/Ichor arrows lol.
Summoning Weapons
Stardust Dragon Staff - I don't usually use it, but when I do, the minion does half or most of the work for me so I find it really useful!