Easily one of the best games ever made. You should maybe even go back and play Half-Life 1, it's simpler and obviously a little rough around the ages these days but I think it still holds up quite well. I'll be interested to see what you think of Deus Ex, I played it right when it came out in 2000 and about 5 times since, one of them just last year. I hope you enjoy it but I think the game may not have aged well for somebody who doesn't love the game in as firm and dogmatic a way as I do haha.
The story was pretty interesting as far as I'm concerned. Nice change of pace to a more Clancy-esque, tighter focus. Every Call of Duty game I've played has been great (granted I've not played CoD3 or the last generation console versions) and I really can't understand anybody's assertion that MW2 was dull. The games are a fun homage to that bombastic style of overblown action and play amazingly. You're right about the AI, some of that stinks, but really the CoD games are well respected and such a financial success for a reason. They're all great fun so long as you don't take them/yourself too seriously.
The new Dante is a hipster. Hipsters are annoying (at least where I live) and the fashion is a fad. New Dante will, in 20 years, look exactly as silly as if the Fresh Prince of Bel-Air had been in a 1990 version of Devil May Cry (due to some bizarre and unpleasant time warp). It is either a) a pessimistic and patronizing piece of marketing nonsense or b) a misguided, blinkered decision made by somebody with no self-awareness or sense of timelessness; somebody caught up in the fashion themselves. Devil May Cry games have always been at least partly about stylishness, but this new design is not stylish, it is fashionable. There is a difference.
I love this. The Yakuza games are some of the least wacky stuff that Japan puts out and the idea of them spending the last 5 or 6 years building up that reputation and then deciding "NO, FUCK IT - ZOMBIES." That's awesome.