ok guys I have some thoughts here, I know they are late for the original poster, but I am sure there are other people turning 30 this year!
I turned 30 last year, and my GF of 5 years surprised me with a trip to the Belgian Grand Prix (Lewis Hamilton and all that!). I was amazed, embarassed (about the kind of money that would cost), and absolutely chuffed. I never would have treated myself to something like that, even though I've watched it on tv for 20 years. It will be something that I will never forget, it was the best present anyone ever gave me.
If you think the 30th is a special occasion, you should think outside the box. As a couple you have probably been on many a weekend away, think of something that your OH would not even dream of doing themselves.
Now it's my GF's turn this year, I have no idea how to live up to the present she got me!