I've had a couple of requests for comparisons and I found some polishes in my stash that were a lot alike, so Comparison Wednesday it is! I apologize for the variety in backgrounds, but some colors wouldn't be accurate on a white background and some didn't like the black background. I did the best I could with it since lighting wasn't really coorperating either..
Anyway, I have no less than four comparisons for you today! Here's a little overview.
Some colors are way darker irl, but again, that's due to the background..
Left Misa Dirty Sexy Money, right Catrice I Sea You! The colors are a little too dark, but you can see that they're pretty much identical. Dirty Sexy Money is a tad bit more blue, but I don't think you could tell these apart when I wore them together as a mani. 
Left Color Club Electronica, right Nfu Oh 117. Both are deep purples with red and blue shimmer particles, but Electronica is a bit darker so I'd say these are no dupes of eachother. They are siblings though, so if you own one of these two, you probably won't need the other.
Left OPI Dating A Royal and Essie Mesmerize on the right. I would call both of them medium blues, but they are no dupes. I've read somewhere that these are deadon dupes, but they're obviously not. Dating A Royal is more intense, colorwise, than Mesmerize. The latter is a bit brighter. No, these are not dupes. If you're not really into blues, you probably won't need both though. 
This one is not as faded and light as my picture let's it appear, but I couldn't get a proper shot. I will try again later this week and add a better picture when I managed to take a more accurate picture.. Anyway, left is Orly Prince Charming and right is Essie Mink Muffs. Both are taup-ey cremes, but Mink Muffs is more pigmented and is warmer than Prince Charming. Mink Muffs and Prince Charming are not dupes of eachother.
Left RBL No More War, right Pieces It's a Camouflage. They are both in the army green category, but that's all they have alike. No More War is way darker and greener than It's a Camouflage so no dupes here either.I hope this was helpful :) Again, if you have suggestions for a comparison, please let me know and I'll see if I can do one for you!
Thanks for stopping by!