This is a fantastic kickdrum VSTi for your creative minds. It was built by AMVST for InternetDJ.com and you can download it right now for free (or a small donation if you are so inclined). Some of the features include ADSR Envelope, State Variable Filter with LP, HP, BP, BR, and Peak, 10 Kicksounds including TR-909, TR-808, TR-707, TR-606, TR-505 and 16 programs.
You'll need Cubase VST 3.7 or higher or other VST 2.0 compatible host software. If you can't afford Cubase, just google to find some free software sequencers that are VST 2.0 compatible.