I keep geting lag spikes on Minetown and its really anoying is there a way to fix this? (Lag spikes is where it lags for five to ten minutes and you cant do anything.)

Relog?

Oh dayum new tag

if you can supply more specific details as to what may be the cause, we can help. In most instances, logging out and back in greatly reduces the lag, but if it is a certain area causing the lag or some other issue, we need to know to be able to address it.

Try turning graphics to fast, render distance normal or below, and performance to max FPS. This has helped me the same way on the FTB server when I move and it glitches out.

Also getting OptiFine really help too

That too.

Protip: Close other applications that are un-nessisary aswell.

Makes a great difference to me when I close skype, steam and google chrome!

Allocate more memory. This helps a great deal. Just google how to do it, it's very simple.