Parts

1802, 2650,
6502 CPU, 6503/6504/6506/6507 CPU, 6510 CPU,
6520 / 6821 PIA, 6522 VIA, 6532 RIOT, 6526 CIA, 6551 ASCI, 6556 VIC, 6581 SID
6809, 6809E, 6309, 6309E, 6844 DMA, 6847 VDG, 6883 SAM, 3242 DRAM MUX, 8202 DRAM MUX, GIME
8085, NSC800, 8255 PPI,
8271 FDC, 2791/2793/2795/2297 FDC, 765 FDC
Z80 CPU, Z80 PIO, Z80 SIO, Z80 DMA
8088/8086,
68K CPU, 68901 MFP
ATMEGA32,
AY38910, AY38912, AY38913, SN76489, SP0256
CRTC (6845, 6545, 46505), CRTC 6545 Application Information
16C552, SN75185, ADM208
PAL, IWM

Memories
2716, 2732, 2764, 27128, 27256, 27512 EPROM
2132, 2332, 2164, 2364, 23128, 23256 Mask-Programmed ROM
DRAM, SRAM (8-bit), 2114, 6810

Teletext:
SAA5050, SAA5281, MV1815

RAMDAC:
IMSG170, IMSG176

PCF8563TF4 Real Time Clock
DS75 Thermometer
24LCxx Serial EEPROM

Connectors:
STEbus, Arcom Analogue I/O, Arcom Digital I/O, Arcom PC I/O, Opto-22 I/O
ISA bus, PCMCIA, ATA (IDE), Compact Flash (CF),
Secure Digital (SD) and MultiMedia (MM),
SmartMedia (SM)

Misc:
Quadrature encoders
Oscillators
Reset circuits

External links

The pages above cover chips that I wanted to make notes about. That is, parts commonly used by hobbyists, popular 'antique' machines, or projects on my site. If you can't find what you want here, try:

datasheet4U. Access is free, unlike other similar sites.

A Set of Standard Microprocessor Programming Cards by Jonathan Bowen of Oxford University.
These ASCII cards have been widely copied, the link above takes you directly to the source.

National Semiconductors Linear Microchip series (LM386, LM2917, LM3914, LM3915, LM3916 and many others)