The second one because you'll be able to wear it many more times so it is worth the money. All of the other dresses are only suitable for very formal occasions like a military ball or a cotillion or for being on the red carpet at the Academy Awards. They are not worth the money since you like we will only wear it once or twice in your life.
I like the first red one (with the lace underlay).
• Those rip easily. If you or yr friends are gna wear any sharp jewelry... watch out! lol.
• Those are all the rage, ever since that For Love & Lemons brand got hot. I wouldn't be surprised if other girls are wearing the same dress. (If other girls are also wearing a more classic style, that's not as bad, right? lol)
If you don't go for that one... I'd avoid the high slit, and I'd avoid the low décolletage. Just waaaaayyy too many chances for a wardrobe malfunction, in either of those cases.
Personally I think you would look better in the blue and silver dresses compared to the reds.
If you're brunette, I would go with red. If you're blonde, I recommend blue. If you're skinny, go with the mermaid style. If you're curvy, I would go with the more flowy dresses that show off the waist.