I can usually find something redeeming even about movies or shows I otherwise dislike, and I can appreciate and recommend it on this part of the whole. I rarely find something with absolutely nothing to recommend it.
Like I could watch one and just like the reality created and want to see it, or one character I felt was a standout, or even hating the plot and characters but love the concept. Or even just an unusual path to take a stock character type or plot.
Oh, sure. (Although these days I rarely watch a movie that, even if I don’t like it, isn’t “good” at least to a lot of people. I ain’t got so many days on this earth that I can watch shit anymore.)
The exception would have to be Star Trek Into Darkness. I am still enraged just thinking about that movie. I cannot think of any redeeming or even interesting facet of that piece of shit.
On the other hand, we just saw again the deservedly ridiculed “Plato’s Stepchildren” episode of TOS. It’s incredibly dumb, but damn if the actors aren’t giving some really good work in it.
Yeah, I can appreciate that an actor is giving it all he’s got in a losing effort to save a lousy script, or that the cinematography is the real star of a movie. There have been a few that I thought were total clunkers, however.
There’s a William Burroughs lecture on writing where he says “a film with a few good minutes is really a good film”. Pretty sure it’s early here: Class On Creative Reading - William S. Burroughs - 1/3 - YouTube
I am the type of person who will watch a film, be bored throughout, and then the ending will be kind of cool and I’ll think “yeah, it was worth watching that”. Death Proof is one.
No. There’s a level below which I cannot watch. It’s relatively arbitrary and subjective, but one I can’t ignore.
I can watch what I consider to be a 2 1/2 or 3 star movie, but would watch a 2 star movie maybe once and anything below that hopefully not at all, but I do tend to overlook things if there’s an element to the movie that I like. Sometimes I’ll watch a movie just because I like the subject matter or theme even though I don’t like the particular choice of actors or script (or vice versa).
I can definitely appreciate the setting of a movie even if I don’t like the plot or characters. Twilight is one example, I dig the Pacific Northwest.
I have a thing for cheesy science-fiction and pirate movies made during the 1950s. I don’t know why, but I enjoy watching them even if I am laughing and/or groaning most of the time. Maybe I’m just yearning for my lost childhood, or maybe I can see why they’re considered classics after all. I tried to get my daughter (age 20) to watch some 1966 episodes of Batman with me on the premise that they were real “classic” TV, but she didn’t bite. (On the other hand, I practically had to strap her in a chair to watch Pulp Fiction a few years ago, and she immediately fell in love with it; I guess she just doesn’t trust my tastes in cinema a priori.)
When it comes to films like They Saved Hitler’s Brain and Ninja vs Mafia, the reason why I watch them is clear: They’re great unintentional comedies!
Why watch third-season episodes of TOS at all?
BECAUSE THEY’RE STAR TREK, DAMMIT!!!* 
*The same logic applies to most episodes of TNG, though to a far lesser degree, IMHO.