Torontonians please feel free to add to this...!

GETTING HERE:

If you're staying downtown, Porter flies into the airport on the Toronto Island. I believe other airlines also fly to this airport now, but Porter has great service. (Complimentary wifi, coffee, tea, water, snacks, beer, sandwiches... cute flight attendants.)
https://www.flyporter.com

GETTING AROUND:

Airport Limo: (416) 820-8300
www.torontoairportlimo.com
Always on time! Book easily online, and they will text you when they arrive. Comparable in price to a taxi.

Beck Taxi: 416.751.5555
Escort approved!

Or if you're feeling more thrifty...

Express Bus to Pearson Airport:
1-800-387-6787
http://www.torontoairportexpress.com
Cheap! Comfortable! Wifi on board and plugs for your laptop. Many places to catch this bus - Royal York, Delta Chelsea, etc. More info on their website.

Bixi bike rental: https://toronto.bixi.com
No seriously, it's neat.

TTC
Public transit costs $3.00 in cash, tokens are $2.50. Unlimited day pass is a steal @ $10.
http://www3.ttc.ca/Trip_planner/
http://crazedmonkey.com/toronto-transit-map/ (Google map with TTC routes over top. Very helpful.)

WHERE TO STAY:

There is already a post about hotels I think but here are a few...

5 Star:
http://www.thehazeltonhotel.com
http://www.ritzcarlton.com/en/Properties/Toronto/Default.htm

Boutique:
http://www.germaintoronto.com (Two locations, go to the one on Mercer w/ Victor restaurant)
http://www.metropolitan.com/soho (Lovely!)
http://www.gladstonehotel.com/hotel  (On the West end. Rooms decorated by artists)
http://www.thedrakehotel.ca  
http://www.windsorarmshotel.com
http://www.pantageshotel.com
http://www.thompsonhotels.com/hotels/toronto/thompson-toronto (New-ish!)

Big:
• Hilton: http://www1.hilton.com/en_US/hi/hotel/TORHIHH-Hilton-Toronto-Ontario/index.do
• Sheraton: http://www.sheratontoronto.com/index.html
• Hyatt Regency: http://torontoregency.hyatt.com/hyatt/hotels/index.jsp?null
(The ugliest building in Toronto, used to be a Holiday Inn but now it's a Hyatt.)
• Intercontinental in Yorkville: http://toronto.intercontinental.com
Across from the museum!
• Intercontinental on Front: http://www.torontocentre.intercontinental.com
• Four Seasons: http://www.fourseasons.com/toronto
• Park Hyatt: http://www.parktoronto.hyatt.com/hyatt/hotels/services/maps/index.jsp
Great spa, if you're into that sort of thing...  
• Westin Harbour Castle http://www.starwoodhotels.com/westin/property/overview/index.html?propertyID=1084
• Royal York: http://www.fairmont.com/royalyork  
Right across from Union Station.
• 1 King West: http://www.onekingwest.com
Located right beside King subway station. If you're here for an extended trip, they offer rooms with small kitchenettes.

FOOD:

I am a foodie so I can suggest some great restaurants... but you'll have to ask me out first.  

Torontonians please feel free to add to this list of inside tips!

I am also a Beck Taxi girl and, in my personal time, a Bixi bike girl. I'm glad Toronto brought the bike idea to town. Montreal, among other cities, has had it for a while and it's a popular thing.

The spa at the Ritz is second to none in my opinion. I've been treated a couple of times now and I absolutely love it.

As far as hotels, I'd add Windsor Arms (www.windsorarmshotel.com) as well.

I'd also add the Cosmopolitan to the hotel list, it's close to the financial district with a nice modern decor and a great wine bar in the lobby. Also the rooms have kitchenettes (or full kitchens) which is always a bonus if you are staying more than a couple of nights.
http://www.cosmotoronto.com/

For restaurants I always recommend checking the Toronto Life guide, it's searchable and has some great reviews on some of the best restaurants in the city - of course I'm sure it's not as good as just asking you but it might be helpful.
http://www.torontolife.com/restaurants/

I especially like the bike rental idea

Good to know about Beck Taxi. I usually use Royal. I often tell them I'm travelling with a small dog, so I don't get *ahem* any religious extremists.

Windsor Arms is good, but small, and their front desk doesn't miss a thing. If you are an escort, dress for business - suit and pearls - to avoid hassle. No street trash!!

I love Cambridge Suites, too. And the Grand is on a rough street (Jarvis), but it's an overlooked gem.

The Intercon on Bloor has Proof Vodka Bar, and Michael - the head bartender - is lovely.

The discerning man will skip the Yonge Street strip clubs and go down to King St to For Your Eyes Only. Cleaner, better class of people.

Enjoy your stay!

What great info,thank you very much for posting this!