⌘ – ⌘ – ⌘ – the Command Key symbol
⌥ – ⌥ – ⌥ – the Option Key symbol
⇧ – ⇧ – ⇧ – the Shift Key symbol
⌃ – ⌃ – ⌃ – the Control Key symbol
⎋ – ⎋ – ⎋ – the ESC Key symbol
⇪ – ⇪ – ⇪ – the Capslock symbol
⏎ – ⏎ – ⏎ – the Return symbol
⌫ – ⌫ – ⌫ – the Delete / Backspace symbol
⇥ – ⇥ – ⇥ – the Tab Key symbol
Courtesy The Apple Logo in Unicode; Command, Option, & Shift Symbols in Unicode; and Special Key Symbols. The last one is ultra-complete.
Additionally, there's another Enter key symbol: ⌅ (a "projective"). It's very similar to ⌤ (an "up arrowhead between two horizontal bars"), but it was also used to symbolize a column break.
The projective was used more commonly on Macintosh keyboards to symbolize the Enter key, and the up arrowhead between two bars was more in software menus.