It all depends on what you want from your vaporizer!
There are a few questions you need to ask yourself.
Am I vaporizing flower or concentrates?
Do I want a portable option?
How much secrecy do I want in my option?
I'll break down my favorites in each category
As a non-portable option The Volcano is obviously the best choice, quality craftsmanship and the ability to pass a bag of amazing around a room makes it the obvious choice for the at home vapor fans. The Concentrate Pad is equally amazing, making it my long time favorite.
For flower on the go I love a PAX it's simple and discrete and the PAX 2 has an amazing Simon says game that makes it play the beat to "Funky Town" when you win! I personally like the larger chamber and mouthpiece of the original, but my betrothed loves her PAX 2. Cleaning the PAX can be a chore, but reliability and usage it is one of my favorite out and about toys. As a side note, I recently had a friend by a Firefly 2 and thought it was pretty amazing and it has both concentrate and flower options, I think it is a better concentrate smoker than flower (the bowls were harsher and came out a bit darker than my typical vaped marijuana, but it may have been the supply.) If you are looking for something a little less "popularized"
For Concentrates, or as I call it the times you really want to get messed up, I'm a huge fan of the Cloud / Keymaker products, their basically the same thing. For the amount of smoke you get from such a small cheap product it's quite amazing. I don't feel bad when one breaks (as opposed to my, Atmos/Dr. Dabber Ghost/Everything with coils breaks.)
I do own a Dr. Dabber Boost and I freaking love it, it is technically a portable E-Nail, and yes that is amazing as it sounds. It's handy dandy carrying case and easy nail replacement makes it dear to my heart. I don't think it's technically considered "vaping" but it does an amazing job on the go or at home. I've taken mine camping (must have generator) to weddings and all sorts of fun events and it's always the show stealer.
Finally if your looking for a good battery for your vape cartridges I would always suggest using a pen with a button over the Auto-Draw! My local head shop sells a X-Vape that also does cartridges and it is the way to go.
Obviously this is opinionated but these are the things that have worked great for me.