If profitability is not your concern and just for a hobby or a test

You could start mining at a low or no cost and just use your existing PC's, CPU mining at the most


Best gear always depend on your requisites

you may require:

- lowpower cost with a decent hash

- Higher Hash and dont need a low electricity cost

- Low price gear with a decent hash over a certain coin algo

- High price Gear with a decent hash with a wide range of algo

- Higher hash, Low power cost, High pricing gear with risk of low or "0" resale value

basically, mining is not a want to buy candies in a store and choosing with a best taste from other people then buy

you have to consider your own environment and own taste which suitable and defines whats best for you