I need a melee weapon in NV, which one is best overall?

Oh Baby! is the best melee weapon (I think.) You find it at the back of Charleston Cave near Jacobstown. It's pretty easy to get. It's a unique supersledge by the way.

Yeah but oh baby! is expensive to keep in good condition I think Knock-Knock is better financial wise

Knock-Knock is a unique fire axe found in camp searchlight's fire station

The problem with that is that it's harder to get. It's really irradiated and there's so many ghouls. I'm scared to go there an I'm level 27

this and
what you should do first thing is raid repconn and search all nightkin for rebar clubs they do decent damage and they dont wear out very quick so you have time to get more which you can get at black mountain from fighting mutants another melee weapon is the chainsaw but they are rare and need constant repairing but have hell of a DPS and rip people to shreds in about 5 seconds but you have to take on all the fiends in vault 3 and get it from motor runner

Chance's Knife is available near Goodsprings, if you have a shovel. Unique Combat Knife. They've each got their perks, like Chance's Knife doesn' eat much AP at all, so you can go crazy with it in VATS.