So my girlfriend and I have been together for 2 years, we are very serious about each other. We will most likely get married eventually, but until then, what are some romantic but still fun dates that we could go on?

Cute ^_^ . Well, it kind of depends on where you live and what you like to do. The best dates and gifts are usually something to do with a hobby or something you and/or she likes..
Generically good date places are of course, Movies, dinner, bowling, laser tag, arcades, day & walk on the beach (if you have a beach you can get to), day at an awesome shopping center, a night at a semi-fancy hotel ;).. or some combo of these..

Cooking or baking something together; making a meal together and then eating it. This is seriously romantic and cute and sexy.

My wife and I have been married for two years but have been living with each other for 5 years and seriously cooking together is the best thing we do together. It's real easy to if you can follow directions you can cook. Check out Allrecipes.com - recipes, menus, meal ideas, food, and cooking tips.