The first one is okay but could be a lot better if you had moved the couple away from the tree in background and used a wider aperture (I haven't checked the EXIF), it also looks like there has been a considerable amount of 'digital' fill flash used in post processing which gives the image a washed out look and lacking in contrast, I've had a quick go with small file and added a vignette to try and focus the attention on the couple, it is probably a bit strong but I have done it like this to try and demonstrate the point:
**Image removed at request of OP**
The second shot appears to have few blown highlights and some of this could probably have been avoided if you dialled the flash down a bit. Composition has already been mentioned by Ali so I won't go over it again.
Again, I agree with Ali on the third, make it a square format and it should look much better.