Firstly dont upload on youtube if you showcase your production, the shitty quality makes it very hard to comment on the production. Soundcloud and reverbnation works pretty well, even myspace is better than youtube. Anyway from what i could hear u need more eq-in, the bass is still too raw imo. To make ik phatter, bigger, filthier or whatever u wanna call it, I suggest to split the freqencies, so you got a low-end bus and a mid/hi bus. This way u can procces the mid/hi with some effects like reverb, distortion etc, without making the low-end muddy. If the bass isnt low enough u can always add some nice sub under it, sine works very well imo. It pretty much about layering + resampling it to get a real nasty bass. Hope this helps. Good luck!