The Walking Dead is a point and click, highly story driven game. You (hopefully will) get emotionally invested with the characters and enjoy the story through making your own choices.
Resident Evil 4 HD is a more action orientated survival horror. Honestly, I'm not sure about the story too much, so I can't really comment on how good it is. I've heard people like it, but I could never get into it.
It's really based on what you're after. Action or an interactive story driven experience. If I were choosing between the two, I'd go Walking Dead each time. I like the Resident Evil series a lot, but never really enjoyed 4.
"My name is Spartan Jay, the greatest MW3 player of all time. Because I am on your team, this team will win" ~ Spartan Jay
I've never played The Walking Dead but Resident Evil 4 is my favorite Resident Evil game to this day. The same is true for most people I know who are in to the Resident Evil series.
Mechanics of Resident Evil 4 are almost exactly the same as Resident Evil 5 except the story and overall layout are more appealing and there's no "in between mission" period (shopping is done through a vender who shows up now and then on your journey.
I don't know if it's just the HDTV screen or the claimed graphic enhancement but the Resident Evil 4 sold on the playstation store looks as good as any other PS3 game.
BTW. There's a foe on Resident Evil 4 who's obviously modeled after Osama Bin Laden.
'In this great world full of stuff that's neat there is one thing that cannot be beat. It's the feeling so sunny when your squeezing a bunny" ELMYRA DUFF