Like with most camping equipment purchase decisions, the choice of the tent boils down to your requirements in terms of size and camping location. These days, tents come in a variety of size options ranging from a couple option right up to accommodating 8 people or more. You also need to decide whether you need a tent which has separators on the inside to create 2-3 virtual rooms or just one large one. However, also factor in for the all the equipment that you intend store inside the tent, since a tent for two people would end up being a real squeeze if you want to put in a cooler.
The choice of camping will decide whether you need a tent that needs to protect you from rain and snow or just one that needs to have maximum ventilation to keep you cool. If you are planning to go to a location which has a high incidence of mosquitoes, then a tent with mosquito nets for ventilation.