How do I keep my roommates cats off the counters and other prohibited areas?

My roommate has been living here since August and her cats just wont learn to stay off the counters. I have tried a squirt bottle which is very effective when I am around but very inefficient when they think I am not around. I would like to avoid a -mat but do want something that will keep them off permanently. (I have tried double sided tape and tin foil and both deter the cats.) I do think that part of the problem may be that she coups them up in her room all day and sometimes for two-three days at a time... I will talk with her about that... but otherwise, I am really, really frustrated. I dont think a shock is the best way to go and I also have a lot of countertop space so it would be expensive... any ideas would be greatly appreciated.