Basically you have the exposed-bridge atties such as the 306; then the 901 and 510 models. Larger 801 is also a classic. And eGo, of course. There are different brands and SPECS/ versions to each; for example the CISCO 306 vs JOYE 306. The ohms may vary; regular resistance, LRs and HV. Then you have hybrids such as the HH. 357 which is a "designer's atty" so to speak. There are Dual
coils versions. And reparable atties, as well, such as Genisis which is a concept by Raidy original and implements a stainless steel mesh oxidized as a wicking to the coil, intead of the standard fibres. You then have cartos; the traditional ones with filler (such as classical Kr 808 D-1) and different varieties of CEs or clearomizers, fluxomizers or others which contain no filler at all. Giantomizers and Apoloe, etc. Then you also have
tanks which are set ups for cartos mostly. Or the "T" versions to common atties in general.
This is just a referential, very general, but you could move on from here by googling each one mentioned which might lead you eventually to more specific versions, brands and types as you search.
I guess there must be a list in the ECF's library... Don had a great guide which was very complete... You might also wanna check that section...