OK, I have others I could throw in, but I'll add a potentially controversial one to the list:
Play B-Spec
B-Spec - seriously?
Why would I even suggest it?
Well, from personal experience...
a. You don't know the true meaning of bored with GT5 until you've become bored with
B-Spec.
b.
B-Spec is the ultimate grinding and cash-making machine that will allow you to buy any and every car you could ever want in GT5.
c. You're missing out on some great prize/free cars with B-Spec, such as the Mazda Furai, Toyota 7, and Red Bull X2010 S. Vettel - just for hitting Level 35!
d. Becoming bored with
B-Spec is a great motivator to give
A-Spec another try - even if it means you'll play
A-Spec with a DC3 controller versus hooking up a steering wheel.
(Just my $0.02... Thanks!)
Peace...