In order of obsession:

• Rilakkuma
• Totoro
• Alpacasso
• Hannari Tofu
• Sentimental Circus
• Mamegoma
• Capybara-san
• Monokuro Boo

I tend to prefer San-x characters, but I also really like Crux, Q-Lia and Kamio. Basically you cannot go wrong with those 3, either. I don't fancy Sanrio much, honestly.