There ar emany switches one can purchase to act as access switches in the LAN environkment or the server farm access layer.
There are the 3750s, 4500s, 6000, etc. Some switches have modulaqr chassis and others are fixed, like the 3750...
So what criteria shoul done use to decide which would be the best switch. If I have say, 200, users, a 3750 stack could do the trick, or a 4506/7, etc....
How is your design planned? How spread are the users?
If you need L3 switching in access layer, look at 3750 upwards if not don't. You may need to look into cost per port in detail, including if there is a cost for rack space.
Depengin upon your physical topology, you may need to look at two locations to serve 200 users - eg opposite corners of the building (assuming UTP, as 100m can get used up very quickly) which may mean 100 users per location - that is not much above 2*48 port switches.
What is the impact of users being off air for a while? If it is something like a trading floor, you may want the high availability features of 4500 upwards.
Basic office work, no L3, 100 users or so I would look at 2950/2960 type switches.
I would probably skip 3560s and go up to 3750 if I was looking at up to around 150 users per location, and wanted L3 but did not need full HA. If the HA is a requirement, I would look at 4507R/4510Rs, or if the ports per location is nearer 300. If absolute uptime is important or huge user density then I would
look at 6500.
So, basically It depends!
Criteria are L3 requirements, port density and availability requirement.