I need a opening title for YouTube videos. Where can I get music/sound effects for that?

Do you really need one? I find most them annoying and out of place. Why don't you just come up with some kind of "Catch phrase?"

For example when jon4lakers starts everyone of his videos, he says "Whhaaaaatt's up everyone?"

Or if could be as simple as SoldierKnowsBest's "Hey, what's up everyone. SoldierKnowsBest here..."

Stick a picture of yourself in a retarded smiling pose and some death metal over it.

If you have any skills with 3D art or video editing, you could make something yourself, and then overlay music you like. Try Blender 3D to make the intro, and then put the stuff together in something like Premier Elements, and add some music you like and that fits the mood of the intro. Or you could just have a nifty catchphrase at the beginning, like "I'm here to save the day... and I look FABULOUSSSS!"

http://incompetech.com/m/c/royalty-free/

This guy has TONS of royalty free music. The quality is pretty good.

Quite a few different movie editors come with music that they let you use in your videos. Try looking around in the 'Media Browser' or whatever it is called in your movie editor, there will most likely be a few sounds clips that you might want to use.

I use thecn they have to be edited in sony vegas :) I will post later more pages, I don' t remember where I have saved them lol I used one of their projects in one of my videos I was planning to use in Machinima although never send the video but I still have it in youtube xD you can watch it here.