I will "do a full juiceme" and write up s brief review of all pictures. My ratings are a combination of technical and aesthetic quality of the entry, how it IMO fits the theme and other subjective factors.

1. Maemish (storage media)

The photo is so dark I had a hard time determining what is actually in it. I can see the CD just about make out the HDD but the rest is in a complete darkness. Even after you explained what I was supposed to see I can still not really see it. I see you tried some artistic composition with objects lying across each other (or was it a coincidence?) but it kind of lost the effect because of the darkness.
My rating: 1/10

2. mosen (pink blossoms)

A really nice shot bursting with colours. The open flowers are nicely in focus and the buds are somewhat blurry, which may be a coincidence but it looks deliberate and adds a nice effect and an impression of an intended message: "look at these flowers, and BTW, there are three more to come!"
If I had to pick on something, it is not clear whether there are three open flowers or four. It looks like there is one flower growing on the other side of the twig and we can see the back of it, right in the middle of the picture.
My rating: 8/10

3. Fellfrosch (dice)

Unlike mosen's picture before, yours is almost monochromatic but one would barely notice (without focusing on it specifically) because the red is so vivid. I like the fact that the focus is on the die in the middle, not the ones in the foreground. The light and shadow play gives the shot a nice dramatic effect, although the shadow in the top right corner is a bit distracting.
I was hesitant what to thing about there being five dice rather than three but "three of a kind" are mercifully grouped together with the other two slightly separated so it actually works out rather well.
My rating: 8/10

4. levone (sheep)

If you had not told us the subject of the photo were the sheep then I would have not guessed. It is hard to tell whether the creature in the front is a sheep, a dog, a bear or some mythical creature and the two at the back are barely noticeable, especially the one by the shed, which looks like a white smudge. I thought it was a dog. It would also have helped if the focus was on the front sheep and not on the tree behind it. And it would definitely have helped to try to group the sheep a bit closer together.
Other than that, I really like the composition, although, like in Fellfrosch's case, there is a distracting element, this time the rail in the foreground. On the other hand, the trees and the sheds at the back are a really nice touch.
My rating: 7/10


5. Juiceme (some kind of artistic installation)

It is hard to tell what it is. Good job you said "art", as that explains everything. The metal frame in the foreground is out of focus which is probably intentional but I am not sure what to make out of the white/blue thing at the top. I like the light play but cannot get over that thing, it is too distracting.
My rating: 6/10 (it would have been 7/10 without that blue thing)

6. eson (stone urns)

The whole picture is slightly out of focus. Other than that, the angle and the cropping are just right. I also like the fact that one of the three urns is a different shape and colour. It may have been because that's what you had available but it looks intentional and gives it a nice touch.
My rating: 7/10

7. wikiwide (branches and wires)

The image has disappeared so I can only review it from memory. To be absolutely honest, I was struggling to tell what was there three of. Also the wires across half of the picture were rather distracting. It would have helped to zoom in on the subject (unless the wires were supposed to be the subject, but I could not see how). Also shooting against the sky is always tricky. It sometimes helps to shoot things like that with the flash on, although it might not have helped in this case since the subject was so far.
My rating: 3/10

8. pichlo (archery)

An altogether wonderful picture with not a single fault
Just kidding, juiceme would not say that. He would say it is "too small". Not that it would matter in this particular case since minute details are not important but he would say that anyway.
I like the colours and the focus on the target, with the ends of the arrows with the fletching being slightly out of focus. The green netting at the background adds to the mood. Maybe experimenting a bit with the angle to fit the whole arrows might have improved the composition, as might if the arrows did not cross one another.
My rating: 8/10

9. robthebold (Easter eggs)

A lovely thee fitting the season. I like the colours. I would have used a bit more aggressive cropping, there is too much grass in the foreground. The dead leaves are a bit distracting but the random shadows (from a tree just behind you?) compensate for it and add a nice touch.
My rating: 6/10

10. catbus (bird footprints on a car bonnet)

You sure like your car The footprints are very pronounced, almost artificial. I am not accusing you, it is meant to be a compliment. Not often do you get such sharp bird footprints. The reflection of the trees add a nice atmosphere.
Unlike in robthebold's entry, though, I think the crop was too aggressive. You could have moved slightly further, zoomed out or perhaps taken the shot in portrait.
My rating: 5/10

11. Pentona (purple flowers)

It is hard to fault this picture. The composition is just right, the focus is where it should be and the colours work really well. I particularly like the hint of more flowers at the background. They are (quite rightly) very out of focus but that is a good thing.
I would have moved the camera ever so slightly to the right to move the flowers bang in the middle horizontally, but left them where they are vertically. Or cropped the left 20% off.
My rating: 9/10

12. peterleinchen (three Jollas on a kitchen hob)

First of all, I am impressed that you had three(!) Jollas to take a picture of. I can see what you were trying to do with the composition but I cannot help it, I find the kitchen hob a bit distracting.
Other than that, the picture works pretty well. I like the colour scheme, it kind of reminds me of an old cartoon (Calvin and Hobbs?) where a father was fooling around with his son by telling him that the world in the past was black and white and old black-and-white photos were colour pictures of the black-and-white world.
I do not know how you managed to achieve the effect that the two Jollas on either side are sharper than the one in the middle, but I like it.
My rating: 5/10

13. nh1402 (Durdle door)

A lovely photo of a lovely place but I feel that the fitting with the theme is a bit forced. You could at least have said that it was three cliffs.
The composition is perfect, although the door itself is lost in the dark. It might have helped to try it at a different time of day, although I suspect there might not have been so many bathers at a different time. I would definitely not change the angle, I think this was just right. Also, although the door may be lost in dark, it adds to the nice moody effect with the water around it. The random rubbish in the foreground (bottom right) is distracting and, sadly, disturbing. Humans are such pigs.
My rating: 9/10

14. spfoo (mangos)

Good composition and colour scheme, including the table top. I even like the odd mamey (never heard of it before!). I somewhat less like the edge of the table in the bottom right. You should have moved the camera slightly to the left.
My rating: 7/10

15. Macros (skyscrapers at night)

You say three towers but I can see at least six But fair enough, I can see what you mean.
The photo is surprisingly sharp for the light conditions, a good demonstration of what can be achieved with a good camera and stabilization.
I do not know whether the light at the right was a deliberate part of the composition for a dramatic effect or whether you just could not find a spot to cut it out but the photo would IMO work better without it. Also, I would like to see the towers' feet, unless there was something in the way or the ground level was particularly non-photogenic. Other than that, the composition is just right, with the towers bang in the middle, their tops gracefully receding from you. Moving slightly to the right would work even better but then the light in that corner would get even more in the way so I think you found the right spot.
My rating: 7/10

And my vote goes to... 3. Fellfrosch.

There are a few entries that I rated higher but I cannot help myself, this picture just speaks to me.