The chain tension is fine, and the chain line is straight. But the chain is still somewhat noisy and it's driving me crazy! Should I lube it up some more, or is it just my crappy cog? Help me out everybody.

Maybe you need a new chain?

argh sorry I forgot to mention the chain isn't even a day old!

clean it check you cog and cr teeth and loube it

I found that 1/8 is a bit louder than 3/32 and that eai cogs are bit more quiet that say a Surly cog or the dreaded cyclepro cog.
I just got a super toughness chain and it is a lot more quiet than the Kool chain (bmx) I had on before.

that my 2 cents.

What size cog and chain? Also, how tight is your chain? I know you said it was fine, but if it's over tight it will be loud. Lube it up and ride for a few daze. Sometimes these things have a way of working themselves out.

1. Loosen the chain- 1/2" up/down play is ideal.
2. Clean and lube it.

This will solve 99% of chain noise.

-1/8" chains are a little noisier than 3/32".
- A new chain on old cog/ring may make a bit of noise for a little while as everything hasn't worn exactly together yet.

I think any new drivetrain esp 1/8" will be a little noisy to begin with, and then quiet down as everything wears in with everything else. My 1/8" KMC chain/ Surly cog/ TA ring drivetrain was very loud at first and pretty chill now, ~900 kms in.

Man my experience is totally opposite. My (new) EAI cog is loud..I've tried serveral chains, all with the same loud results. My surly cog is quieter, or rather, it was quiter before it got really worn. But if I compare them when they were bot unworn...the Surly was much quieter.
My Izumi track chain (EHS) was loud and clanky on all of my cogs, and it was stretched after 400 miles and I was a real Nazi about keeping it clean and lubed, and properly tensioned. What a waste of $50. My cheapo $6 KMC BMX chain is much smoother and quieter.

16t 1/8 cog, 1/8 KMC chain. I cleaned up everything, and when riding it's almost like I have no chain at all. But it's a lot more noisey when the bike is turned upside down, which, well doesn't really matter, but is it normal? Thanks for all the help!

Its noiser when its upside down because you are probably in your garage (or somewhere quiet) and you probably have your face right up to the drive train. Out on the noisy street, with the wind, and your head way up there, any minor noises from your drive train will be unheard, or at least seem quieter.

Maybe the chainring bolts could use some tightening? Or maybe a little grease on them?

Problem solved, new 18t cog (euro-asia) purchased, no noise. I needed a new bigger cog anyway.

I run an old school suntour superbe pro cog an fsa ring and a kmc z chain and when it is clean dead silent like the ninja it is

I like the ninja reference. Its way better than having to read those ******** "butter smooth", "like butta" etc. comments about chains and bearings. I'm really really sick of the butter analogy.