OK, just done a bit of working out, and if things go as plan...
My 375th will be something at Gilroy Gardens.
My 400th could be Revenge of the Mummy at USH, but, is more likely going to be something at Six Flags Magic Mountain (one of the last things we ride, so, it'll probably suck, yay!)
My 425th will be something at Disneyland or Castle Park.
My 450th will be something at Movie Park... :S
And my 475th COULD be something at Tusenfryd, or one of the Brighton Pier rides depending on when they happen.
But, should end the year on about 475-80! Only 110 credits to go...
And it'll be fun to see if it actually works out ANYTHING like this xD