I recently wrote a post about a great little dripper but I can't leave out one of the drippers that helped put them on the map, and that is the Smoktech rda aka Octopus (Smok RDA article here for newer members who may not be familiar). Though its design may not be the most original with its striking resemblence to the ERA (original name, right? "Easy Rebuildable Atomizer" I believe it is, lol), it's probably the easiest to open with its ridges and inward slanted top. Then they used ridged thumb screws so no need for a screwdriver or allen wrench, and last you never have to "remember" exactly where the coil is to position the air hole, you just line it up with the outlet between the two o-rings. It's pretty good sized too. The rda definitely deserves some recognition and is a perfect starter rda!