There is also VGmix http://www.vgmix.com/
Used to be a damned fine place, but crashed and lost everything a few times with the site being re-done each time.
As for OCRmix, You won't be likely to get your music in there, the standards are quite high when it comes to music these days. Basically how it works is, you post your music, then there are elected judges who judge your music, and if you get enough votes it goes on the site. (used to be a semi judge at OCR, would have ben in the voting crew if it werent for my lack of vocabulary when it comes to music, but knows what to listen to for things that are wrong and right in music, just lacks the words to express it.)
As for newgrounds, I have a healthy dose of hate for that site, they vote most things as pure gold that are terrible. The standards aren't very high, too low infact. (Not that I could do better, but still.)
As for your music, I'll have to be a little harsh, the first one is dreadfull, it really hurts the ears, badly infact, it is a bit of a strain to listen to.
The second one is by far the best, but Honestly, All I hear is som low rap beats and everything repeating it's self over and over again, as someone already said, that is a very bad thing since it bores the listener fast. I'm not too impressed by the length ether. But mostly, this is a rather boring mix.
I would sugest in the future to work on learning to use synths (or instruments) properly, possibly writting out the music first if you know how to and playing it. (or even seeking out the music written down on musical notes if you can read music.)Working on good making synths sound good can be hard. A tip can be if you are going to sample music and use it over and over again, put in some more synths, mix up the melody, posibly add in a few more samples that would fit. But what helps the best if you do the music from scratch, no samples. You organize the music in a style of music chosen (bosa nova, rock, metal, techno, whatever.)Then after you chose the style, pick out the proper synths in a music creation program (I might sugest tweaking them or looking for synth plugins on the net for the program.) then listen to hte piece and try to mimmic it in the music in style you have chosen.
Things to avoid are being repetative, and mixing up the mood or the tone of the music a bit. A good reference is if you have played FF13, you will notice almost all musical pieces are sort of remixes of one tune, and how you can convey a lot of moods and tones by using the same theme played in a different way with different instruments.