I wish when I started, someone had given me the advice, I am about to give you. Would have saved much money and aggravation. I got many E-Cigs but here are my top 4.
The Titan 510 (many 510's on the market) Thin, the size of a pen, very good vapor, throat hit for this category. With a Pass Through on 5.0 v is fantastic, battery stinks last 1 - 2 hours. Price very reasonable 76 USD with PCC. Complete and ready to go.
( Next 2, takes same batteries and can adapt to 510, 801 and 901)
The Silver Bullet Mod. Very beautufull, runs 3.7 and 6.0 v. 3.7 too weak for me, 6.0 too strong for me, long waiting list to get. Very shiny, gets marked up easy with finger prints and scratches. Great deal for the money, 114 for main case only, have to buy everything else to get started.
The GLV 5.0 V. Heard by many that 5.0 is the perfect vape. Makes sense to me since 3.7 too weak for me and 6.0 too strong for me. Many have said the 5.0 is the Perfect Sweet Spot of Vaping. From experience with my Titan 510 with Pass Through at 5.0 V would tend to agree. Haven't actually got it yet but love my 510 when using with 5.0. Long waiting time to receive. Cost 128 USD. Ready to go.
The GG Transformer, my best and favorite. Also a Mod, runs 3.7 and 6.0 v. Again 3.7 to weak for me, 6.0 too strong for me. Better vapor and throat hit than Silver Bullet. Cost much more also, 170 USD, even longer wait, but well worth it. Has accessory ASF that lets you vape all day without refilling, only E-Cig that does that.
Would like to add, this is stricktly my subjective opinion. I am not affiliated in any way with any E-Cig company.
Also the Silver Bullet has wires and soldering which does something to resistance. The GG has no wires or soldering so has no affect on resistance. Am not an electrician, but have been told that because of the resistance factor, the GG is better than the Silver Bullet. I like the GG better but it also costs more. The Silver Bullet is american made and an excellent value for the price. The GG is hand made.