I've always liked the Garfield TV specials as well as Garfield and Friends (yes,including US Acres)....I must be one of the few that likes it...I still love the running gag they had with Booker and Sheldon,where they'd ask Orson to put ninjas into whatever story he was reading them (usually a fairy tale like Cinderella or Rumplestiltskin)...
As for replacement voice actors,I usually don't mind them,though I do prefer that they at least sound something like the person they're replacing...
As for the original comics,I used to really love the series as a kid,and looking at some of the books I have,the comics back then were funnier(I also have one of the US Acres comic strip books,which I find hilarious;I'd like to find more,but I'm not even sure how long the comic strip ran)....Nowadays,it can be funny at times,but it seems more hit-or-miss (though I do like that Jon and Liz ended up getting together)....I'm a big comic strip fan,my all-time fave is Calvin and Hobbes,though currently I also love Pearls Before Swine (I love all the references to other comic strips/characters,plus that the creator is also a character),Get Fuzzy,Fox Trot,For Better or Worse,and Frazz,to name a few...