Married 7 years, here, and we still enjoy each other's company like the day we were married (or started dating).
Trick is to do things 'from the heart'. *Most* women (at least, the kind you'd want to have a relationship with) don't value the monetary value of something as much as sentimental value. Gifts like signed or first editions of their favorite books (usually possible to find for surprisingly cheap) win a LOT of points. Finding out her favorite wine (if you are of age) and finding a bottle from the year you were married is ALSO worth a lot of points.
Writing poety (no matter how cheasy) or 'love letters' both are well received (don't be a psycho about it and write one or ten every day - special occasions are fine), and this will be true forever (literally, figure Valentine's day, her birthday, your anniversary at LEAST. At a rate of 3 a year, they will stay 'special' and have exactly the same level of success for as long as you stay together).
Other than that - doing new things. Bed & breakfasts are a good idea - meet new couples (that run the place), find things to do.
Women (again, the good kind) tend to not go for tourist-y destinations as much. Find quite, 'romantic' spots, areas of special meaning, etc. For example, one of my wife's favorite books as a kid was 'Misty of Chincoteague' (it's about a horse). It's about as quite an island as you can possibly imagine (during the off season), so we found a B&B on the coast and spent a week there. She loved it to death! No real tourist spots or events, just parks to hike in, beaches to walk, historical monuments to check out, etc. A LOT of fun, and surprisingly affordable.
Also, buy a digital camera! Again, something to not go 'psycho' with, but women LOVE having their pictures taken. (Careful not to go too far....if you freak her out, that's bad). Still, at least once or twice a day on your vacation, try to get a picture of her being cute, or a romantic picture of the two of you. (Plus, when you post how successful your vacation was, and everyone in ATOT asks for 'pics'....you're covered!)