Worst - Titan 2 - while it's cheap and portable and heats up quick and does the job, it's too hot and harsh for me. Not very tasty compared to others.
Beyond Worst- those coil-based e-cig-like "vapes" that actually don't vape at all AND burn out in a few weeks. My pre-fuckcombustion.com adventure. Yuck!
Best Group Vape - Vapir Rise 2.0 - I love the sit-back-and-vape feel of the hookah mode (complete with my added long hookah hoses). Nothing to teach newbs, nothing hot to touch, nothing to stir or poke, no buttons or lighters to mess with - just hand them a hose. Great for a group of 2+, but if you have a party, you can also go bags. Ever want to convert a combuster who says vaping doesn't get them high, give them a bag. Works every time.
Best Personal - My trusty NO2 - I know, I am in the minority, but I mostly vape medically, and I don't want a giant hitter. The NO2 is dependable and almost maintenance free, and I can load in a ridiculously small load and still get medicated. Not really great for more than 1 person, and terrible for a group, and not even very portable, but still my personal fav.
Special Mention - The MFLB. My only real issue was the push-in battery which hurt my already hurting hands, plus I hate any vape I need to mess with while vaping. However, my daughter just loves that little guy to death. So it really depends on your vape style.
** GREAT thread - I read the entire thing which goes back to 2012. A real wealth of info for the newbie or experienced vapist. Simply fabulous.