Checkbox and Radio Buttons

1) FancyForm
2) CRIR: Checkbox & Radio Input Replacement
3) Ryan Fait’s Custom Checkboxes & Radio Buttons
4) ARC - Adam’s Radio/Checkbox Customization
5) prettyCheckboxes
6) jQuery checkbox
7) Articles & Tutorials On Customizing Checkbox and Radio Buttons

Select / Dropdown Box

1) JavaScript Image Combobox
2) jQuery Dropdown Check List
3) Custom Select With Icons
4) ComboBoxes Using MooTools
5) Select Replacement
6) Additional Select Box Customization (Won’t Work If JavaScript Disabled)

Almost All Form Elements

1) Custom Form Elements (CFE)
2) Emblematiq Niceforms
3) jQuery Plugin: jNicex