IMO when it came to MP I think that Bo3 was probably that one COD game that you could grind and play non-stop. The movement along with the then-new jetpacking mechanics were smooth and fun. When it came to guns, you could run anything. It even felt satisfying to hit shots and the reactive camos were also pretty sick. Guns like the VMP, Kuda, Locus, Brecci and XMC were very fun to use. Although I wasn't the biggest fan of Supply Drops, it felt nice getting DLC weapons. To me the other games that are on the A tier of COD alongside Bo3 would be Bo2 and Mw2. Bo4 is considered by many to be one of the worst ones made in the series, but I'd say its worth giving it a try.