One truly has to have a little patience when we move on public transportation. Remember the early 2000's when Expense Reports included taxi rides to from the airports to the hotels, to client dinners and maybe a quick trip downtown for shopping? Well now I am paying my own way and so far so good, one just needs patience.
Sound Rail to SEATAC is a fairly cool ride. It takes you through neighborhoods which will benefit in growth from the Rail traffic. It ends in Tukwilla, but with a quick bus service to SEATAC. December is when the Rail will drop you right off at SEA. Travel time is about 35 minutes and if you have a late or early flight departure / arrival it will get you to the airport without having to wake someone up and chance a schedule. During business hours it travels every 6 minutes and Off Peak every 15 minutes. I included a link to Sound Transit website.
Total Cost: $2.50 One Way
When you arrive in Las Vegas ( McCarran Airport, again they general push is a taxi, car of bus shuttle to your hotel. Cost for this service is between $12-$20. Some hotels have pick up for you: so check with your hotel. I took Public Transportation, specifically Bus # 108. You can get off the bus at the Las Vegas Convention Center and take the Monorail which will get you fairly close to your hotels on the strip. I included a link which has further information on where to pick up #108 at McCarran Airport. Don't be afraid to ask someone where to pick up the bus. I included a link for further information on the bus service.
Total Cost: $6.75 One Way