I have always liked Federal ammunition. Usually went with the Premium line in order to get the premium bullets such as the Nosler Partitions, Ballistic Tips, AccuBonds and now Terminal Ascent bullets. All have consistently shot MOA or better in my rifles. For my 7MM STW, I still haven't tried handloading much for it as I get 1" groups @ 300 yards with the 160 gr AB, and I have a good supply on hand...maybe at some point I will need to, but am not there yet.
So far, really impressed with the Terminal Ascent on game performance and accuracy (but have only used in one cartridge to date - 6.5 Creedmoor. Looking for some for 6.5 PRC and 300 WSM, and have the 270 Win ammo to try in my new to me LH Steyr Mannlicher Model M FS).
Remains to be seen if it will earn as high an overall standing as the AccuBond has in so many cartridges and rifles over the years.
And the blue box has done quite well in some rifles too...the 200gr load will shoot better than 1/2" groups @ 200 yards in my 338 Federal.
I have always liked the on game performance of the Winchester Power Point ammo, so will not hesitate to buy and shoot it, and use it regularly in my lever actions, and other rifles if it shoots well in that particular firearm.
I like the performance of Norma ammo, and have used it from time to time in the 6.5x55 when I could find the Partition ammo. The Hornady Light Magnum Euro Spec also did well, when it was in production. Unfortunately, I do not have of that left.
And I have had good luck with the Weatherby ammo (Norma manufactured) in the 270 Wby and 338-06. No longer have the 279, and have a good supply of the 338-06 with the 210gr Partition on hand.
I also like the Nosler ammunition when I can find it for certain cartridges. While it might not always be the fastest load, it has generally been pretty accurate (MOA and better) in the rifles I have used it in. And I will take accuracy over velocity anyday!
I have little experience yet with the HSM ammunition, but so far the rifles I have tried it in have all shot well (MOA or better). Still have to try out the 250 Savage, 10MM, and 375 Win ammo.
The other ammo brand that I have some, but have yet to try out, is Buffalo Bore. Looking forward to the performance results in my firearms. (35 Rem, 358 Win, 10MM, and 41 Rem Mag)
Of note, I have always bought a variety of ammunition to try in new rifles to get a feel for what bullet and velocities that particular rifle will shoot well, before moving ahead with handloading. And when I find a particular factory load that the rifle likes, I buy 5 boxes so I always have back up on hand in case I run short in handloads. Best to be prepared! Better to have and not need, then need and not have!