Depending on your budget, you can't go wrong with a DNA 166/7 (Therion for example), or DNA 200 or 250 (Triade, which is 3 batteries), or SX Mini QMini, they are the most reliable and accurate mods out there, but they are not cheap.
The Asmodus Minikin V2 is a great mod and cheaper than the others I mentioned.
The Sigelei Fuchai 213 is good providing you don't need more than 150W, because it doesn't do the 213W that's promised.
I suggest you watch some Youtube reviews.
On saying that, the Alien is also a very good and cheap mod, I think you just got unlucky with the one you received.