#50:
The high point of the series for me. Rome was my favourite city in the series and was fun to explore, and Ezio was a really great character. The management element of the Brotherhood assassin's guild was great fun, and little tweaks to the combat made it a bit more varied and attack-minded, rather than just relying on counters. It also introduced the multiplayer to the series, which I thought was a very interesting concept, and actually required a bit of thinking which was nice.
#49 clue - for me, the best karting game that doesn't involve Mario