Aspiola inspired me to create this list as we both seem to be in agreement that most of the restaraunts in Helsinki are disappointing, overpriced, or both. Hence I bring my worthless culinary opinions to you, my English-speaking brethren.
1. Anitiokia Atabar This is my personal favorite. A Turkish restaraunt in Kamppi. The food is just out of this world, and the prices are reasonable (average main course 12-15 Euros). You'll find it on Eeerikinkatu right off of Abrahaminkatu. Don't be fooled that downstairs it looks like a hole in the wall. Upstairs it has a great ethnic feel. Even has live belly-dancing on weekend evenings.
2. Singapore. This is the best Chinese restaraunt I have found in Finland despite the fact it is not chinese (Malaysian). Cheap food, big portions, nice owners, and it actually tastes like something! This can't be overstated as you all know that Chinese food in Helsinki is bland beyond words. Lapinlahdenkatu nearly across the street from Maria Hospital.
3. Eerikin Pippuri. This is a kebab place as all kebab places should be. The tomatoes are bright red, the lettuce crunchy and green, and the food excellent. Eerikinkatu between Albertinkatu and Fredrikinkatu.
4. Mount Everest. Most of you know this one. Lapinladenkatu. Amazing Tibetan food. Not the cheapest, but very reasonable. Try the Mango Lassi.
5. Santa Fe, world trade center. I had to think before putting this one down because I hate the place. Poor service mostly owing to the way the place is designed. Still can't ignore the fact that it is really good Tex-Mex for a damn good price. Also has the only year-round terrace in Helsinki.
Enjoy and Bon appetit!