celador on 19 January 2017
For me, Brotherhood
2 was the first game I played, and I really enjoyed it. Brotherhood refined it, and added some cool stuff of it's own that actually worked and added to the experience. After that, feature creep. One game even had tower defence, which was appallingly bad.
Black Flag is in second for me, the only game after Brotherhood that added something worthwhile to the formula. If it has come earlier in the series, it probably would have been my favourite.
