The "ONE" Blade - Which Would it Be?

For a de--Personna. The ones in the blue box.

For my Feather AC, Feather ProGuard.

Polsilver with GSBs and Platinums a tie for second.

Feather
You can tone down a sharp blade but you can't tone up a dull blade

Yeah i see alot of astra sps out there. My second favorite blade is Gillette Silver blue because of its sharpness/smoothness but it some razors, its just not as smooth to me as my Astras, and it feels a bit too aggressive. Astra SP is goldilocks.

SE razor-GEM PTFE (no contest)

Injector-Chinese Schick Injector

Artist Club-Schick Proline P-30

DE-way too many to say there could possibly be just one (Brazilian Gillette Platinum-Plus, Personna Medical Prep, Astra Superior Platinum, Voskhod, and Gillette 7 O'Clock Super Platinum [Dark Blue box] to name a few).

Astra SP, not my favorite blade, works in every DE razor I've put it in and they are very economical.

Gillette Nacet. Every time I try something new(including pol-silvers, GSB, feathers etc), including those that are supposed to be super sharp, when I come back to Nacet, they are as sharp as the sharpest but much smoother.

Gillette white box platinums.

Gilette Silver Blues

My favorite blade is the Perma-Sharp.