So I have a short list of good ones here. Good for the apartment or small container garden. I have no doubt that others have their favorites and we would love to hear about them!
The ones pictured above are available from Lee Valley and perfect for quick watering for smaller plants. - they screw onto the top of plastic water/soda bottles. Also makes great use of your bottles before recycling - and you can leave a bunch around your apartment as a ready reminder to water.
An atomizer is perfect if your apartment runs dry. Your ferns and orchids will love you for it. Because the water is atomized, it doesn't leave a mess. Also refreshing for your face. I have a glass one from the NYBG shop and it only cost about $12.00.
Dramm and Haws will easily match your new set of Crocs. Both companies have a great line of watering cans made across the pond but easily available here in the U.S. They are easy to fill, hard to spill, and beautifully balanced to make watering easy and more precise, even with the higher capacity cans.
And if you want to spend no more than $2-$6 on a can, Ikea's are really not that bad. I saw them hanging in Dmitri's on the UES the other week and they are very festive. Also better designed than most cheap plastic cans.