Green Park is a great 3 star hotel. The staff are very friendly and willing to help in any way with bookings, directions and information in the local area. There seems to be a very personal touch in the service. Our room was great, lovely and big, very clean - like the rest of the hotel. A big bed and modern bathroom, playstation 2 and computer with internet in every room. Very accomodating for families - playstation 3 in the lobby with free bike hire , playgroud out front and a nice pool.
The only down side was the location - takes about 10 minute walk into town, but its uphill when returning, which can get tedious. BUT the hotel do offer free bikes which help. There is also a bar beside the hotel and a take away pizza place which we ate by the pool some lazy evenings with a bottle of wine.
Overall great hotel.

We stayed in this hotel for 3 nights, the double room (102) was very small you could just about manage to walk around the end of the bed. So don't bring a cat to swing around! We did see some other rooms as we walked along the corridor and they appeared to be bigger. Located about 15 mins walk from centre, parking on site good and free internet and use of swimming pool. Apart from the size of the room, the hotel was good.

Asked for directions at the Tourist Office and was sent to the wrong area of town.
Thin walls and adjacent bedroom windows made for sleepless nights and building works on new property at rear of hotel meant early morning call when builders started.
Staff were very friendly and helpful

My wife, two children and I stayed at the Green Park Hotel for 3 nights in July 2008.
First, the bad things about the hotel: The room was unbelievably small, with one double bed and a bunk bed, and no walking space whatsoever. I requested for a larger room at the front desk, but they didnt have any available. There is no room service to speak of. The hotel is about 15 minutes walk from the waterfront.
Now, the good things about this hotel: The room rates are reasonable, and the breakfast was quite decent. The manager lady was always very helpful, and so was her husband, who was always willing to drop us off at the train station (from where you can catch shuttle buses to either Gardaland or Aquapark). There were quite a few things to do for the kids, like an outdoor pool, table-tennis, mini-soccer, and Playstation. They also sold Gardaland tickets at cheaper prices.
In a nutshell, its not a bad hotel at all, and you can consider staying there if better options are not available. The Bella Italia campsite looked great, but unfortunately we we didnt know about it until we were already there. Maybe I'll try it out next time!