Ticketing, fares and travel info

Travelocity - Plan air travel, and purchase tickets too
Expedia.com - Ditto
Tripadvisor - General info and reviews
Trip It - site for keeping your travel info organized
WebFlyer mileage calculator - calculator for FF mile distances
Rome2Rio - discover how to get anywhere

Airlines

Alaska Air/Horizon Air
United Airlines - check on flight info, delays, etc.
American Airlines - ditto
Delta Airlines - ditto again
British Airways
SeatGuru.com - the source for airplane seat information

Hotels, Rental Cars & Rewards

Hilton HHonors - Hilton, Doubletree, Embassy Suites, Hampton, Homewood Suites, etc.
Marriott - Marriott, Residence Inn, Courtyard, Fairfield, etc.
Holiday Inn Express - Free hot breakfast bar!
Hertz - cars
Award Wallet - track rewards programs
Points.com - ditto
Vistana - "A better way to see the world"

Other

Super Shuttle - Airport shuttle service
Garmin - GPS devices, etc.

Cruises

Norwegian Cruise Lines - Freestyle Cruising
Disney Cruise Lines - At sea with Mickey

Yakima Area

White Pass Ski Area - Great skiing west of Yakima
Washington Mountain Pass Report - As it says, pass cams and all
Mount Ranier National Park - National Park Service site
Mount Ranier National Park - Alternate "expanded" site

Travel Planning

Fodors.com - Fodor's travel guides
Washington State Ferry System - Info, schedules, etc.
Rand McNally - Road trip guide
National traffic and road closure information - Links to each state's DOT sites
Washington's DOT site - Pass info, etc.
AAA - American Automobile Association (Washington)