Happy New Year, Tom!
Most of my daily user tools like my square tools or material-specific general purpose tools, are simple M2 HSS. For the tools that have delicate tips, like my knife tool and threading tools, I use HSS-cobalt blanks because the small contact areas of these tips get really hot really fast. The higher red heat resistance of cobalt helps these tools retain their edges longer.
As for brands, I much prefer Mo-Max and ETM (Iscar) M2 HSS, although most US-made HSS will be fine. I also like HSS blanks from Japan when I can find them. When I am experimenting with a grind to see how the angles work, I use cheap Chinese HSS blanks and they seem to work just fine, although I have convinced myself that the edges don't hold their sharpness as long as high quality blanks. I doubt that you would see a difference, though.
For cobalt, I prefer Super-Mo-Max in M35 (5% cobalt) and M42 (8% cobalt). Most high cobalt Rex/Crucible blanks are good, as are the high Tungsten blanks from Rex/Crucible and Vasco. Most cobalt blanks from US makers are also very good. ETM makes some really good M35 cobalt bits but they're expensive. The Chinese cobalt stuff is okay but I do not rely on their claims of 5/8/10% cobalt because there is no documentation to confirm it. Still, I have used some Chinese cobalt and found it to be pretty okay.
If in doubt, go with US-made blanks. Mo-Max was made in the US until the late 1990's, I think. Then they moved production to Mexico but the blank quality from Mexico is still amongst the best you will find. Other US brands are Rex/Crucible, Morse, Do-All, Vasco/Teledyne and many others.
Hope that helps.
