After 5 years in surveying- I have seen most adverse possession cases handled between the two parties and a surveyor with lawyers only used to do the paperwork, not go to court to argue!!
Joe S- Work it out with your neighbor before sueing him. You bought the house with the knowledge that it was on the property line??? With minimum setbacks in consideration, that would have concerned me from the beginning. Can you explain the size the of your lots, distance between homes, etc. (if you need more questions answered)?
Bonnie- Same concerns as Joe's, property size, street size that divides your property, etc. Is he currently using "your" property in any way, access, driveway, storage, or has he been maintaining it? It will vary from state to state, but here in Arizona, it's generally 7 years of continued use and it's considered yours. Compensation can be sought after that period, but it is much more susceptible to the judges opinions. More info will definitely help!