It's so easy to eat on the cheap in Portland.  This town is one of the best places to go out and have a good meal for a reasonable price.  It probably has to do with the use of fresh local products.  As everywhere, happy hour is the best bang for your buck.

 Breakfast:

Voodoo Doughnut  (22 SW Third Ave Portland, OR 97204-) - Funky donuts for less than 5 bucks a meal

Wong's King (8733 SE Division St Portland, OR 97266) - For Dim Sum, it seems that no matter how many people go or how many dishes you order, everyone ends up paying only about 9 bucks per person for a hearty and diverse breakfast

 Lunch:

Best Baguette (8308 SE Powell Blvd Portland, OR 97266) - Can't really beat $2.75 for a sandwich, can you?

Happy Hour:

Saucebox (214 SW Broadway , Portland , OR , 97205) - This hip bar/cafe serves wonderful pan-asian small plates during happy hour that range from $1-4. 

Portland's City Grill (111 SW 5th Ave, Portland, OR 97204) - Sitting on the 30th floor of the bank building, this place has beautiful views of all the surrounding mountains.  The ambience is enhanced by the piano placer and the plush furniture.  The happy hour menu is both cheap and delicious, so get there early so you can stake out a good booth or table. 

Basil Bar (3135 NE Broadway St. 1st FL. of Sweet Basil, Portland, OR 97232) - It's nice to get little samples of tasty Thai food at a fraction of the price.

Ten 01 (1001 NW Couch St, Portland, OR 97209) - This is a hip conteporary place with a very high price tag for dinner, but their happy hour is very reasonable.  This is a great way to see how the other half lives (and eats) without paying what they do. The food itself is tasty and innovative

Jake's Grill (401 SW 12th Ave , Portland , OR , 97205) - Seafood at a fraction of the cost. 

Dinner:

The Farm (10 SE Seventh Ave Portland, OR 97214) - You can actually taste how fresh the food is here.

Iorio (912 SE Hawthorne Blvd Portland, OR 97214) - Comfortable Italian food.

Cha! Cha! Cha! (1208 NW Glisan St , Portland , OR , 97209-3015 ) - Of course a local mexican joint needs to be on this list!