M-tren is easily my favorite. Agree with everything the posters above said about it. To help with the lightheaded feeling, make sure to eat carbs and drink TONS of water after dosing.
High dose var and drol (anadrol or superdrol, both pretty equivalent) are tied for second here. Drol gives better results in terms of pure numbers, but it comes with a lot of added weight, so if you’re not a SHW that’s something to consider. Superdrol is “dry” weight, so you’ll have a better look in the gym, but the bloat from anadrol is easily lost during a weight cut, so it’s really just a difference between price and the sides you get from each. I find anadrol’s sides much more manageable, personally. That said, I only use var and m-tren now.
I get nothing from halo at doses less than 100 mg, which isn’t worth it to me when I can just take a little bit of m-tren instead.