When it comes to sequels and remakes, my reaction to them is probably similar to yours--something like a *facepalm* followed by an eye roll. It's even worse when it comes to the horror genre. With a few exceptions, horror remakes tend to be very indicative of the time during which they are made (i.e. Halloween, The Bad Seed or even Psycho), with themes that have proven difficult to modernize. But when it came to rebooting the Japanese horror classic, Ju-On: The Grudge (2002) and Spanish horror film, Rec (2007), Hollywood got it right.
It helps that both American remakes, 2004's The Grudge starring Sarah Michelle Gellar and 2008's Quarantine starring Jennifer Carpenter, are practically carbon copies of their predecessors. Also, director Takashi Shimizu helmed the two Ju-On films as well as two installments of The Grudge. Since he kept control of the story, it worked out for both him and the audience. Both the original and remake scare the bejesus out of the audience, while the remake also preserved the simplicity and suspense. Although Rec director Jaume Balagueró didn't have a hand in the production of any of the Quarantine films (he did the first two Rec films as well as the forthcoming Rec 4), you can tell that helmer John Erick Dowdle (who also co-wrote the remake) really paid attention to the tone Balagueró brought to the story as well as nearly duplicating his inflections in many of the same areas in the film.
I actually ended up watching the American remake of both franchises before I ended up caught up with their foreign language originals. Despite already knowing the story, I was still effectively frightened when I got around to watching the originals. There's something about the modest effects particularly in Asian horror that make you focus almost entirely on the dialogue, which allows the horror to sneak up on you and make it that much more horrifying. Plus, Shimizu's very sensitive approach to the terror that continues to haunt the house's former inhabitants in Ju-On allows you to concentrate on who the characters and get to know their stories. When it came to The Grudge, it was just a matter of taking the foundation of Ju-On and applying it to a sleeker Hollywood lens. Even with that more technical enhancement (which is still far more authentic than many modern horror films today), the remake maintains the authenticity of the original.
Balagueró took a similar approach when he adapted Rec. Whereas Asian horror is often more restrained in style, Spanish horror is more manic, more with quicker pace, but still terrifying. Both Rec and Quarantine did to the found footage genre what very few American filmmakers have been able to accomplish--inciting genuine fear from the audience without coming across sloppy. The sophistication, along with the frenzied yet controlled camera work, both Balagueró and Dowdle apply to the films avoids the campiness of what we've been seeing lately in American found footage-styled movies. Both pieces take the audience inside the horror that demoralizes the lead character, a journalist who thinks she's got her first big break on a story but ends up becoming one of many victims trapped in a apartment complex overrun with the undead. They're also one of the few horror films that are set in an apartment building and not one giant creepy-looking house. This makes it that much more accessible.
Both franchises reignited the psychology of 70s-styled horror, which played more to audience's emotions than their senses. They're less literal and more symbolic, truly excellent contributions to both American and international cinema.