Your Balbinus caught my eye. He's one that I've never owned. I did have a Pupienus sestertius once, and it was a Wildwinds plate coin, but alas, I can't find it online now and have no pics.
@Blake Davis , you have a beautiful collection of Sestertii. I loved your Titus and Caligula most. Titus sestertii have become very difficult to find. I regret never getting one for my collection. Yours is well above average. I started collecting sestertii around 1990. I remeber welll CNG sales on Ebay. I think I got a Galba from them.
You are correct about Titus - I have been looking for a Titus from later in his reign for years but everything offered is too expensive for what are pretty worn coins - unless you want to four figures. But elsewhere on this site I posted a photograph of a Titus struck in Thrace I recently won in a Leu auction that turned out to be one of those bids that you make, NEVER expect to win - and the coin turned out to have beautiful patina, a huge 29 gram flan, and better than the photograph. For the most part this only happens with bronzes - silver is 'what you see is what you get." Bronze is HARD to photograph - been doing it for 26 years and still have problems. I foolishly did not save the photograph of the reverse of this coin. The reverse is also Mars walking right as with the other one I have which is why I did not make a serious bid. But I won it anyway. I think this is COS VIII - I have to look up the date. Thracian mint but the same nose on Titus as the Rome mint and for me the nose says Titus along with the "T" in the inscription. Same celators? Or copied from coins - I am convinced that is what the provincial celators got their models from - not statuary but coins. The patina is nicer than on the photograph. What makes this Thracian?
Here are the last ones I photographed - I have only two more I want to add after these: 1. Severus Alexander - Pax, purchased from a Serbian friend, thin flan but beautiful patina and a personal favorite: 2. Calugula sestertius soldiers - terrific cleaning by Anthony Holmes - the patina is nice even if the coin is a bit rough: Also terrible photograph 3. Gamellus and Germanicus in cornucopia - the photograph is actually better than the coin. I assume that as the Senate became less and less important the SC became relegated to the message - propaganda - that the emperor wanted on the reverse. Perhaps that is why Alexandrian drachms are so interesting, since the celators had more freedom with the reverses. Pure speculation since I am certain nothing went on the reverse that was not approved by the Roman official in charge of Egypt. I guess we will never know.