if you aim to buy to mine eth 1050 or 1060 are the better as hashrates scales good with the price spent  and power consumption

eg :1 1050 ti hashes 14 - 16 mh/s power 30-50w

1 1060 3gb costs 50% more but hashes also 50% more and consumes also 50% more ( 19 mhs 60w  22 mhs 70 w 85w 23- 24 mhs)



1070 will has at aroun 28 but will cost 2x 1060 and will consume also  30  - 50% more


so for eth better smaller cards from nvidia


for other algos then all scales pretty the same so you can chose if you want density for a premium or if you want lot of rig to administer and pay a lil less