100 rouble note, type of 1919 with inspirational slogan in multiple languages. (better reference materials: https://en.numista.com/catalogue/note218376.html ) The same basic design was used on 250, 500, 1000, and more ornate 5000, and 10000 rouble notes.
During the revolutionary period, everyone- various regional governments and military units- was issuing all sorts of banknotes, so a lot of them are still fairly available and cheap as collectibles. There are entire specialized books devoted to trying to unpack it all.
Also my favourite of the Soviet coinage. The poltinnik/half-rouble (https://en.numista.com/catalogue/pieces4623.html ) features a man working a piece of metal with a sledgehammer and anvil, and the rouble ( https://en.numista.com/catalogue/pieces7401.html ) features two men pointing towards a glorious future. These were the first types of coins issued under the USSR designation; previous ones were labelled RSFSR. Later types switched from silver to base metal.