Best lens/accessories for the Nikon D90, please recommend

Have some extras cash and looking to buy some photography equipment.

What lens I have

5.8x AF-S DX Nikkor 18-105mm f/3.5-5.6G ED VR lens

AF Zoom-Nikkor 70-300mm f/4-5.6G

I have filters too but don't know them off the top of my head so just recommend anything!

Well first you can forget that "X" thing when it comes to dslr lenses… That only applies with pocket toys and bridge cameras, not dslr cameras.

Your lenses are fine. I'd recommend a UV filter for each if you don't have one for each. A UV filter does little or nothing to your photos but it does protect the from lens element from scratches and other problems.

Also check your filters for an and and perhaps a polarizer.

Always use your neck strap. My cameras never leave their bag unless the strap is around my neck, never. If you drop this camera because you were lazy and didn't use the strap you'll kill it.
Be very careful.