The blokes leaning out of the window is not an installation.
The glass shelf with WOW on it was interesting, what made it even better was the guy who made the thing got his girlfriend to stand by it all night so people wouldn't put their beer on it. Now THAT'S art.
Then lastly is that Dandelion. I walked past it a few times and thought that is was a bit wanky of someone to just go and dig one up and place it in the corner. However on closer inspection I discovered it was made of bronze and then hand painted. Brilliant!