Any 2-3 star hotel in the center meets your requirements, there are plenty of bars/pubs and so on. Sorry, I cannot recommend any in particular, I have never stayed in a hotel in Helsinki.

All hotels (except one called Omena, a budget place in the center) have breakfast included in the room price. And hotel breakfasts are usually big buffets. You can skip lunch after that.

Of Irish pubs Molly Malone´s is the most popular. Also popular (quite rowdy) is Rymy Eetu, a German style beer house where people dance on the tables.

There is no metro to the airport. There are busses that leave in front of the terminal. They take you to the central railway station which is in the center.

just one warning....everything in helsinki is very very expensive

As Elina says, there is no metro to the airport, but the bus is easy to use to the central railway station. From there you can walk to the main shopping district where there are lots of restaurants, bars, and probably hotels. The streets around there are busy with daytime shoppers and again in the evening; quiet on Sundays.

Only time I stayed in a hotel in town was in an apartment type place over behind the museum. More of a residential neighborhood, so not what you are looking for. I did visit a friend at his hotel by the main bus station/shopping mall. There were quite a few offerings in that area, but to me not as central as the main shopping area/park/waterfront.

we stayed at the hotel helsinki _ sokos chain

great great breakfast - really nice room really cosy and the food was really laid on

we were close to the main station and could walk to the harbour area too

the torni comes highly recommended by tower here - and id trust his judgement cos he recommended the gabelhus in oslo and that was amazing
torni was unavailable when we travelled in may - lots of conferences

I took a taxi from the airport to my hotel which was the Klaus K. I really liked the hotel - I was travelling by myself as well and felt very safe. Easy walk to the esplanade and the harbor & market. Great restaurants in the hotel itself, and also easy walking distance to many others.

You can take the Finn Air bus from the Helsinki airport-it will drop you off at the train station and takes about 40 minutes. Same for return - catch at train station and take to airport. Pick up/drop off is at Terminal 2 (International arrivals/departures). Cost is less than 10 Euro/person and credit cards are accepted.

We stayed at Hotelli Helka this past June - about a 10 minute walk from the train station. I would recommend this hotel! Major shopping mall nearby, as well as shops/restaurants, and tram station is behind hotel. Although we didn't eat at Molly Malones in Helsinki, we ate at the one in Tallinn, Estonia. Good food and prices.

There is plenty to see/do at the waterfront. You can get a good meal at either the Market Hall (indoor) or food stalls (outdoor). Very fresh food at either location. Take a ride on tram 3-it'll give you a great overview of Helsinki - you can catch it at the waterfront.

Everyone has their own definition of expensive, but Helsinki met that criteria for us-that's not unusual for the Nordic/Scandanivian countries I guess. ENJOY!