Ports are like anything else, some good well made ones, some cheaper to the masses.
Also, check out Madeira. Similar but very different and I think you would enjoy it.
Then, look at late harvest dessert wines of both white and red varietals. They are becoming more and more available as the wine buying public becomes more and more educated and begins searching out new wines.
Typically port is non vintage, blended from many in fact. To be a vintage, it has to be 'declared' as such and is usually reserved for the better years. All generalities.
Also, many wineries make ports as projects and often you can get them through the winery but not in the general stores.
Have fun, but limit your consumption, the sweetness can give some nasty feelings the next day
-Chris