• Artvex: 10,000+
• Barry's Clipart: 5,000+
• Bit Better: Those black shadow figures
• Canadian ASLT: Decent collection 
• Clipart Factory: Japanese site, translated into English
• Clipart Heaven: Biggest online collection...probably!
• Eigo Batake: Japanese site, translated into English
• Englipedia's Clipart: If you sign-up (free), you can see more...
• Florida's ETC: 35,000+
• Happy Lab: Japanese site, translated into English
• ill Pop: Japanese site w/ Japanese-ish images.
• MES-English: Collection of about 200
• Purdue Univ.'s J-Project: Bubbleboy and more
• Sazaidas: Japanese site, translated into English
• Spectrum Nexus: Tons of Japanese comic book clipart
• Watanabe's Illustrator: Japanese site, translated into English
• WP Clipart: 17,000+

• Anpanman Characters: All 47 characters
• Calvin & Hobbes Cartoons: All of them...I think
• Nigae Board: Japanese caricatures
• Shiroshi Vision: Japanese caricatures