The list is long, and incomplete.
First and foremost, it should feel like home. It will be the stage setting for the next several years of your life, at least, and it darned well better support your lifestyle, or else it's a nightmare.
After you've figured out that you'd really like to live there . . . among the most frequent condo problems are (in no particular order)
* poor budgeting, resulting in special assessments;
* low owner/rental ratios, which affect financing. Also, it affects livability. Not that renters are bad . . . but if you have 15% renters, that's almost six owner-occupants for every renter. At 20%, it's four to one; at 25%, three to one, at 33%, two to one. The end result is that the HOA winds up being the de facto property manager for these absentee landlords.
* EIFS, and other siding problems. The litigation is lengthy and unrewarding.
* House Rules. Every condo should have them; but, be careful. Banning 125# dogs may be beneficial; banning goldfish and canaries, not so much.
* Maintenance and services. Elevators are expensive, so are swimming pools; they have their benefits. On-site managers, concierges, door(wo)men, all beneficial; all cost money. In a small project, you may be expected to share the chores - wheeling the garbage and recycling to the curb, for example.
No condo is perfect, but no house is either, and neither are we! So, first and foremost - find a place where you'll enjoy living, then worry about whether you can make the details work.
BTW: TU to Scott Godzyk; whenever I show a unit in a condo complex, I will stall around waiting for someone to come in or out so "we" can ask them how they like living there. The technique is to ask, then shut up and listen; if they're shy, ask them one question at a time, and wait for the answer!