All leader diplo screen quotes are somewhere in the game assets folders, wait a minute ... found them:
...\Sid Meier's Civilization 4\Assets\XML\Text\CIV4DiplomacyText
---> for the vanilla leaders
...\Sid Meier's Civilization 4\Warlords\Assets\XML\Text\CIV4GameText_Warlords_Diplomacy
---> for leaders who first appeared in warlords
...\Sid Meier's Civilization 4\Beyond the Sword\Assets\XML\Text\CIV4GameText_DiplomacyText_BTS
---> for bts leaders
Comes complete with French, German, Italian, and Spanish translations. Here's what I've found:
vanilla
- Julius caesar - salad "he made himself" - obvious play on the myth that caesar salad was invented by julius caesar
- roosevelt - martini
- huayna capac - the aforementioned smoked hamster
- kublai khan - "kung pao yak"
warlords
- mehmed II - figs and sherbet
- churchill - tea and crumpets
bts