A list of I²C devices that I've come across when working with Sun and Alpha hardware. Not complete by any means. Mainly a way to discover which devices might be at a particular address.

To search these devices by I²C address, use I²C Address Lookup

Note, that an I²C bus translator can alter the apparent addresses of a device. For example, Sun Fire computers also use address 0x28 for the AT24C64 NVRAM/IDPROM, and addresses 0x58 to 0x77 for SPD memory and other EEPROM's via the SUNW,i2c-imax bridge/expander.

I²C references:

UM10204: I²C-bus specification and user manual
AN10216: I²C Manual
Bridge/Expander
Device Address range Product Page Data Sheet Notes
SUNW,i2c-imax 0x09, 0x0b, 0x0c, 0x12, 0x30 unknown unknown 1
Clock Generator
Device Address range Product Page Data Sheet Notes
ICS951601 0x6e unknown 951601-datasheet.pdf  
ICS9FG108 0x6e 8-output PCIe Gen1-2 Synthesizer | IDT 9fg108e-datasheet.pdf  
Controller
Device Address range Product Page Data Sheet Notes
PCF8584 Programmable PCF8584 :: NXP Semiconductors PCF8584.pdf  
Sun JBus I2C N/A unknown Fire_Reference_Manual.pdf, PIO_ref_manual.pdf 2
Mentor Graphics I²C, Sun Fire I²C, Marvell MV78230 I²C, Allwinner Sun4i I²C N/A unknown Mentor_Graphics_MI2CV.pdf  
DECchip 21272 Core Logic chipset I2C controller N/A unknown ds-0025a-te_tsunami_typhoon_21272_hrm.pdf 2
DAC
Device Address range Product Page Data Sheet Notes
TDA8444 0x40, 0x42, 0x44, 0x46, 0x48, 0x4a, 0x4c, 0x4e unknown TDA8444.pdf  
EEPROM
Device Address range Product Page Data Sheet Notes
AT24C01, AT24C02, AT24C04, AT24C08, AT24C16 0x50 to 0x57 unknown doc0180.pdf 3
AT24C32, AT24C64 0x50 to 0x57 unknown doc0336.pdf  
AT34C02 0x50 to 0x57 and 0x30 to 0x37 unknown doc0958.pdf  
PCF8582C 0x50 to 0x57 PCF8582C-2 :: NXP Semiconductors PCF8582C_2.pdf  
SPD memory 0x50 to 0x57 Memory Configurations: JESD21-C | JEDEC varies  
GPIO
Device Address range Product Page Data Sheet Notes
FM3560 0x37, 0x4e unknown unknown  
PCF8574, PCF8574A 0x20 to 0x27, 0x38 to 0x3f PCF8574 :: NXP Semiconductors PCF8574_PCF8574A.pdf  
PCA9555 0x20 to 0x27 PCA9555 :: NXP Semiconductors PCA9555.pdf  
PCA9556 0x18 to 0x1f PCA9556PW :: NXP Semiconductors PCA9556.pdf  
PIC/Microcontroller
Device Address range Product Page Data Sheet Notes
PIC16F818/819 0x29