justin.tv, check their traffic/interface lately? scribd.com, though maybe that doesn't qualify on interface. shopify.com,
basecamp.com
Its not really that important just something that ive noticed. THen again there arent really any java sites that i can think of that are high load sites that have complex interfaces either. Meaning newer sites. MAybe they just arent in fashion anymore. Or everybody is just moving to ajax front ends.