Which Vivillon pattern did you get in your copy of X/Y? Do you like the pattern native to your region? Did you use it on your team? <3 Here is a list of what Vivillon patterns are obtainable in specific regions/countries.
As far as I remember, I got the garden pattern. It's not too great so I'm pretty envious of other places that got the cool blue patterns. I tried collecting these for a while but gave up.
I got the Jungle pattern since my location was Malaysia/Singapore. I wasn't too happy with it since it was so dull compared to the other Vivillon patterns. I've taken to collecting them but ice got one or two patterns left before I complete the whole set. I've even got the event and Pokéball pattern.
I got the continental pattern, probably one of the patterns I like the least tbh. I like a lot of the vivillon patterns just not the one my country got.
I got polar! Which is luckily one of my favorite patterns. I love the blue and white ones so I was really happy with this one and used it on my team for a while.
I got the Modern Pattern since I live in Texas. It's alright I suppose, but there are a lot of other patterns that I like better. I never used it on my team.
The one that I got had I think the Polar pattern, I don't remember which one it was but i'm from PA so it wasn't a major special one or anything too exciting.
I got the River pattern, which I kinda like but I wish I had gotten one of the prettier ones, but River is still pretty cool
Since I live in the Pacific Northwest, I have the High Plains Version of Vivillon, which I'm not entirely fond of. My favorite is the Polar version. I didn't use it on my team in-game, but I do own one of each Vivillon pattern in my X Version, including the special "Fancy" and "Poké Ball" patterns.
I have the Modern version, that somehow got stuck on my team for the longest time when I first started playing. Actually wasn't a half bad Pokémon really.
Even though I live in Wisconsin where the Polar Vivilon supposedly lives, I ended up getting the Modern Vivilon for my game. ...I find it ironic that the Meadow Vivilon is the default one, yet it's not even the most common by a longshot.
Polar Vivillon was my native one since I lived in Michigan at the time. My pals all live in the same region, so they also got the same pattern that I did. I like its colors a lot, though, so I didn't mind that at all.
I think I either got Modern Or Polar. I don't remember haha. I like both, but there are others I like better.
I got the Polar pattern, which definitely fits with my area's frigid winters, haha. It also looks really great as a shiny, in my opinion- the dark blues and whites go very well together!
I got the Meadow pattern, which I honestly feel pretty indifferent about it---it's not one of my favorites, but I don't hate it either. I really wish I'd gotten the Ocean pattern, though, since it's my favorite out of all of the available patterns.
I don't have X or Y yet, but whenever I get X2/Y2/Z/Whatever, I'm going to temporarily change my 3ds region before I start the game. I'm deciding between Marine (mostly light blue) and Monsoon (gray and blue). But I also like archipelago (reddish). Decisions, decisions! At least I know to do this ahead of time now.