Although I'm no longer a student, anytime I feel nostalgic, I go to Future Cafe and see students stressed out , heads hanging over books and suddenly I no longer feel nostalgic. Instead I sit back and enjoy the paper, one of the cafes massive cookies and a cup of herbal tea.
Situated dead smack in the Annex, this is the quintessential cafe of choice because it's large inside and out (the patio is quite popular come summer), and it serves not only coffee and cookies but real food from a separate section in the back.
My only complaint is that sometimes tables are hard to come by because people stay for so long, and I have yet to sit at a clean table. But hey, that sort of thing never bothered me when I was a student...