Test. Since you are asking this question, I'm going to assume that you are new to gear. You need to use test as your base. Then from there, you can add other steroids to it. There are a lot of great steroids that will get you very hard. Keep in mind that how you look will be a result of your dieting though. So you can take the best hardeners and see little to no hardness if you aren't lean. For a new guy, something like winstrol oral would be great. It's oral so you don't have to do additional injects, which take some getting used to when you are learninng how to use gear. Here is how I would lay it out

1-12

Test E 250mg EW, split into 2 shots a wk

adex .5mg EOD to ED as needed

5-12

Winstrol 

40mg ED

PCT starts 2 wks after last shot