My fav is M201.
Long battery life, no primer puff neccessary, super easy draw (with 4 holes in atomiser and another few holes in battery), cooks liquid in carts most efficiently compared to the DSE, RN, Joye and KR models i've tried. Read my review of it for more info.
Cons:
Parts are not interchangeable with other penstyles except for carts. This could actually be an advantage if you plan to sell it.