Lol.. he doth open a can of worms with that question.

It's like asking what's the best car... everyone is going to say something different.
Plenty of recommendations.
Eleaf (Istick series)... Inexpensive, but fairly good quality.. you get a good bang for your buck.
Sigeli. Good solid devices for their price. Good engineering team, but they can be a bit boxy an non "flashy"
IPV series. Another good device, and a bit better on the eyes. They are a bit more expensive than their competitors, but they're still at a reasonable price range.
Cloupor. Good form, and some of the smaller sized devices. Good price.
Smok. Decent price, and they're even more for the eye candy. They produce good mods, but seem to pack too many unnecessary features in a box mod.
Vaporshark. IMO, they're overpriced for what they are. Very good build quality, but you pay a premium for their devices.
Kanger. They've produced good mods for good price. I think they've balanced things very well, but their product line isn't as big as others.
Those are just some very broad generalizations on the companies as a whole. They have multiple products, and some fit some people more than others. I'd probably try to narrow down exactly what you're looking for... and list specifics.. even if minor. Perhaps you want a smaller mod, perhaps you want one that chucks clouds... You might want to narrow down your search.