Helios 44-2, beast of a lens that you can buy for about 10$ or even find it cheaper. It's a replica of Carl Zeiss Biotar 58mm f/2. For a replica, this lens produces such a great contrast and overall image quality that can easily compare with modern lenses that cost 10-20 times more than this.
Background blur that this lens have is unique, with its swirliness. It also can handle contrast even on strong lighting, like this sunset for example.
With this lens you can also do close up of your subject. No one can argue with a fact that this lens cost just 10$ and that can produce this amazing quality of photos, and when you combine it with post production you are getting perfect results.
Add one macro tube to this and you can get really close and yet preserve very good image quality with a cost of light. With additional external flash, you would get macro lens that can compare with some dedicated macro lenses, there is no doubt.
Overall, the best lens for that kind of money!
