I thought this was the darker end of the red-violets when I was swatching, but it turns out that at least one of them is very deceptive. This is Pretty Serious Kashmir, Milani Purple Gleam (it's hard to read the bottle, but I think it's from the One-Coat line), and Colorstay Bold Sangria.
easily get your hands on. All the Milani polishes with this bottle shape are discontinued, I'm pretty sure, and this version of Colorstay is also discontinued. That out of the way - I like all three of these a lot but I am just fascinated with Purple Gleam. It looks red-violet in the bottle, but on the nail the red stuff just seems to disappear, and it looks more like a blue-violet - or a grape. Somewhere along the way lately I was talking about how I wasn't sure what grape-the-color actually looked like (it was in the entry on Grape Minds Think Alike, which makes sense) but I think Purple Gleam is it. Your mileage may vary, but anyway, this is a stunning polish.
The other two here are more middle-of-the-road dark plummy things. I love plums (which should be no surprise to anybody, if you've been watching the parade of plums from my stash go by recently) so "middle-of-the-road dark plummy thing" is a compliment as far as I'm concerned. They are not much alike, however. Bold Sangria is a creme; Kashmir is a jelly base filled with flakes of various colors. (Actually, calling Kashmir middle-of-the-road is probably a great injustice now that I think about it. It's far too interesting for that. Bold Sangria is a lovely color, but it's a creme. And sorry, it's late and I'm babbling.)