I don't have a particular mascara that is my go to "holy grail" mascara. There are some I favor, but I will always try a new one because I never tried one that is absolutely best than the rest. My favorites thus far have been They're Real by Benefit and Falsies by Maybelline. They're Real is high end, and more expensive, but you can always find it in sets by Benefit in the mini version. The Falsies is quite affordable in any drugstore, so it's easier to try. I recommend it! I also like the Colossal by Maybelline, it's efficient!
Not sure if it's the greatest mascara in the world but I've been using the same one for as long as I can remember: the colossal volume express by Maybelline NY. I use the waterproof one and I've been using waterproof mascaras for so long I can't even imagine using a normal one. I think it's a good mascara, nothing special but it gets the job done.
I like Glam Eyes by Rimmel. It's affordable, doesn't clump on my lashes, and looks nice. However, I've also tried their Scandaleyes mascara (the bright orange tube), and it's not so great. It's got a weird texture. Maybe due to it being waterproof?
I wish I had found the perfect one! I have lots that I like in general, but my main problem is they always smudge under my eyes. The only thing that stops it is using a mascara primer. Right now I'm using ModelCo Fat Lash mascara, and I really like it (aside from the smudging, but that seems inevitable to me now). It makes my eyelashes look long and full, and it's very dark. In the past I've also really liked Avon Supershock Mascara and Covergirl Lash Blast. The mascara primer I use is Shiseido, or Youngblood - they both work really well and reduce the smudging by about 90%.
I'm the same; I'm not dead set one a mascara. Many mascara brands deliver good quality mascara. I personally use MAC, it is a bit more expensive but it is good quality. It stays on all day, yet it washes off very easily. I am happy with MAC, I would suggest it. Their lipsticks are amazing as well; their red shades are gorgeous.