These are things I either currently use or have used in the past and they have reliably performed well for me. Click on the picture to buy for yourself.
I have this flex plate. Can't say enough about it. Probably the best bed I ever used. Everything just sticks and pops right off.
I have this flex plate as well on my main BMG printer, I use the textured side when I want a textured look on my prints.
This is the extruder I have on my main printer. It is not cheap but it's been reliably great for me.
This is the heatbreak I have. I love it. Hasn't clogged on me once. Smooth like butter.
I've used a few different nozzles now. Most caused under-extrusion. The Micro Swiss nozzle has been my go-to.
This is the board I have installed on my main machine. I can't say enough about this upgrade. It is a worthwhile one if you're willing to put in the work.