There is no one best tank for everyone. What works great for me and my juice, may not work well for you and your juice. Like Ghost said it all comes down to preference. I have alot of different tanks/clearomizers. Ce3/4's, Vision Vivi Nova's, iClear30's, kanger Evod's, Protanks, F16, AGR Locking tanks, IGO-S Dripper, AGA-W RBA (starting to hate this one, probably gonna sell it)
It all depends what i feel like using and what mod im using at the time. If im doing yardwork, im gonna grab my bolt with F16 tank or mini mode vamo with a Evod. If im watching tv or sitting here staring at this screen posting vaping stuffs, im hitting the Itaste svd with 6ml carto tank on it! It's all subjective, just like the best juice!
Get a bunch of different ones, stay on the inexpensive side until you determine what you like. I think i'm in the spot where i might be buying a more upscale carto tank in the near future! Just cant decide which right now.