To say, not the meanings behind them...

The Best

• Pomegranate
• Epididymus
• Squirrel
• Blancmange
• Totipotent

Seriously, if you take away the meanings (especially epididymus and squirrel) and just say the words, they're amazing.

The Worst

• Mucus
• Sticky (especially those two together)
• Globular
• Pork
• Chew