There is no better upgrade to a budget or mid priced guitar than installing professional grade electronics: switches, pots, and jacks, or even taking the plunge on some high quality pickups. These upgrades will make a big difference in tone and long term reliability of your instrument.
Here in the shop we make sure to use high quality parts like Switchcraft jacks for example, and Bourns potentiometers. Recently I was turned on to a great product that we are also now stocking in the shop: the Bourns series 82 high quality potentiometers. This item is part of Bourns highly touted Pro Audio line of potentiomters for guitars, amplifiers and audio equipment.
Now you will notice right away that this item has a different look than your standard guitar style pot which has been used for about the last 60 years. First, it has a sealed body which is permanently lubricated. It also uses a conductive plastic resistance track instead of the basic carbon track. Both of these features insure that the series 82 will not wear out or get that annoying scratchy sound, and makes them very noiseless and transparent. Put one of these in and you never have to mess with it again. I recommend highly using them on all volume pots since that is what usually gets most of the use. For tone pots, which are usually not adjusted as often we usually stick with the std units.
For more info on Bourns check out their website at http://www.bourns.com/proaudio/pamm.aspx