I haven't played through Yakuza 3 all the way, but I have played 1,2, and 4. I thought that 2 was the best thanks to it's story, but also gameplay. I agree that maybe the gameplay has gotten a bit stale and the 4 different players in 4 didn't quite fix that. But it's still pretty great and there's not a lot of solid brawlers like it out there. Though I guess the Yakuza games have always been a bit ridiculous, I thought maybe 4 got a bit too crazy with some of Saejima's twists. Don't get me wrong, it was still very fun and enjoyable story wise and they're some of the few Japanese games where there does seem to be decent storytelling, it's just even I found my suspension of disbelief being tested a bit.
Now I skipped 3 basically and one thing I found in 4 was there were a lot of talking scenes without voice acting, basically cheap cutscenes. Two didn't really seem to have that. I guess being this gen and budgets and all it makes sense, but are Kenzen and 5 like this?