2. Good Schools
3. Garage (at least 1-car)
4. Indoor or Garage Laundry (not coin-op)
5. More than 1 bedroom.
6. Some kind of outdoor space (Patio or balcony)
7. Ground Floor Unit
8. Corner or End Unit (not sandwiched)
the neighborhood, condo covenants, ask a realtor, how many have already sold, and at what price, if its brand new construction, ask the realtor, to give you a breakdown, on new condo's in the area, occupancy rates, and resale prices, and "time on market"
School district is not that important to renters, especially with studio and 1br. Most such tenants have either no kid or little ones, not going to school at all. Also, good school district will cost you huge amount of property tax, after all 65% of the property tax goes to school district.
With builtin washer/dryer is good, but do not forget you, as a landlord, has to maintain them. Rent wise with or without builtin washer/dryer not make any difference as you can see in Edison Hollow South http://raspberryct.blogspot.com/ which is currently sold out due to the fact it can easily walk to Edison Train Station to commute to Wall St. My friend Samson from San Jose area came to invest 5 condos here for the reason $200k 1br 1ba condo can rent $1,400 a month. He paid all cash on all his units. Every year he can visit Greater New York City area 5 times, and airtickets, room and board, ...etc can all deduct tax since it is investment expense as long as he visited his units and say hello to his tenants.
You rarely find condo with garage, but once you found one like The Commons http://thecommonsatpiscataway.blogspot.com/ you want to buy and hold it.
p.s. do not email to me, I am not realtor...