Which Cisco switch do you recommend buying for a university lab?

In Goal To teach the student the:

1.basic network requirements.2.Layer2 switching.3.VLAN.4.Security of Ports.5.Port On/Off.6.Tunneling.7.POE

you should use the cisco series or Cisco Catalyst Series in goal for ACL Configuration and more managements.

As per my knowledge is concerned CCIE Security v5.0 Lab Training Certification Course best for university lab. if you don't have knowledge about CCIE course so I recommend Koenig Solutions. 

cisco and cisco switch  for ccna practice

I recommend layer3 switches where you can turn it to router for learning purposes like Catalyst, if not, then Catalyst.

good luck

Ya go for L33550, it will fit for two place as switch and as router also in some places :)

As Per the new CCNA Blue Print they have added lot of new stuff that Siwtches like2960, mostly will not cover entierly. Agree with Mushir Hussain that it depend on your requirements and budget.Chassis base switches are costly but modular. Normal switches3650 would be Suitable

Well, it could vary from campus requirements, users, switch capacity required etc. but for a typical hands-on, catalyst 2960 would suffice, if you find one, or any other catalyst switch.