I have tried many multi ingredient products over the years, single bulk ingrediants, and even made my own stacks, as well as different cycling methods. Most everything was disappointing. Little to no effect on libido or erection quality. However this summer I used(as part of a PCT)
Sustain Alpha
Kings Blood
Libido and erection quality were off the charts. So much so, that I dreaded coming off Kings Blood, and am now back on it. I FELT as if I was 16 again, and had never ran any hormones in my life. I cant recomend both enough. Sustain Alpha I run year round. Will be a shame when I finally run out.
A few years back I do recal having a good run with:
Arimistane
Fadogia
It's hard to find quality fadogia, and arimistane Probably does little to nothing for controlling E2, but I do recall always having some decent results with it in the lower region. Been a while since I ran it though.
Disclaimer: I also ran pharma Clomid with both stacks, at 25mg EOD. Clomid alone does little to nothing for my erections/libido, but the scientific evidence, showing it's positive effects on testosterone can't be ignored.
Chlorophytum Borivilianum - This is a very interesting ingredient. I have a few bottles of Chloro-Test laying around. Out of the many solo ingredients I've run(in this catagory), it is one that I believe I saw some benefit from. However, I never ran it long enough to be fully sure, and further testing is a must.