I stayed four days in Slisko and loved it. Room was clean and extremely large. Breakfast was ok. Staff was helpful and there was free wifi. Main bus station and tram station are just minutes away.
I asked for a room that doesn't face the street and got it, so it was very calm during the night.
They are still rebuilding some of the areas and TV only has local channels, so I wouldn't recommend it to people who intend to stay at hotel all day long. But just for the breakfast and sleep over, it is great.

If I need to stay in Zagreb again, I would choose Slisko.
Sanasy from Sarajevo

Stayed here twice in September, wanted to be within an easy walk from the bus station (5 minutes). It is in a quiet neighborhood. The rooms appeared to be almost new, in an adjoining building that connected with the older part of the hotel on the second floor. Breakfast was a simple affair, just the basics. The hotel said there was wireless internet service but I did not use it. The Hotel Slisko is not a fancy hotel by any means, but it was fine for a night or two.

This hotel is ideally situated for the airport bus, being less than 10 mins walk from the bus station. We stayed in room 115. It was spacious, with a bath as well as a very large shower (you could fit a small family in there), clean and the sheets were crisp and looked new. The furnishings looked new and were bright and cheerful. The lift was being refurbished but the hotel offered us a porter to take up our luggage. Breakfast was the usual continental style consisting of cheese, salamis, yoghurt and fruit juices. I was surprised that there were no evacuation plans on the doors or anywere else and the hotel lacked fire escape signs, although they seem to have sprinkers in the rooms and corridors. I was also surprised that the windows did not fully open and would present a problem as a means of escape in the event of a fire. The area is nothing to write home about but nor is it seedy. There's a bar outside but it was closed when we returned to the hotel at 1030pm. The local bakery though was open.

Our first impression about service was in fact a good one: we arrived late in Zagreb, without a map of the city, and could not find the location. We called the reception from the cell phone and were kindly remotely guided by the recepcionist. But then, in the rooms, the reality was much different: the bed sheets had holes in it, The cover sheets were very harsh, made of a very strong and heavy cloth, unknown to me for this purpose. The bath towels again were full of holes and falling apart in pieces. It's not that the room was not clean, but this appearance is not acceptable even for a cheaper hotel. The fact that the room door did not close on its own and had to be locked with the key also showed the overall bad condition of the room. The hotel was the single cause for us to stay in Zagreb just one night and move on earlier than originally planned...