Coins of some emperors are often not well struck. For example, mid third century coins are often struck from worn dies and the reverse dies are used so much that the reverse type is mushy. But the coins of one third century emperor, Maximinus I Thrax, 235-238, tend to be very well struck--I think on average perhaps the best struck coins of the entire empire. Search for his types and almost every denarius is well-centered and deeply struck. If you seek a really special example you can go for highest grade, or you can seek one where every letter is clear and the dies were fresh. Most high-grade examples of imperial denarii have a weak letter or two and it can be hard (and expensive) to get one without any weakness in strike. However, if you want to try for a really well-struck coin, coins of Maximinus Thrax are a possibility. This coin has wear, but the original strike was remarkably nice. I started a previous thread about his three portrait styles: https://www.cointalk.com/threads/maximinus-thrax-the-giant.251940/ When this coin was offered in January I got it, even though I already had the emperor and type. What a strike!
well, I'm gonna pile-on ... again, great coin!! => here is my sweet Max-Thrax example ... Maximinus I (Thrax) AR Denarius 235-236 Maximinus I (Thrax) & Salus