Yeah I have quite a lot of experience, just be wary that it always ends up costing a fortune in fees, postage and tax
It does usually work out a little cheaper if you're willing to put the leg work in though.
In my experience:
Buyee is the best, but by far the most expensive. I've only had one issue with them (a cheap game that wasn't put in my package) but because I didn't pay for the expensive service they basically told me to bugger off.
FromJapan runs some pretty good offers, especially if you spend a lot with them. FJ used to have a great interface for buying from Suruga-ya, but they recently got rid of it for some reason. Suruga-ya was great for buying cheap console games because the fee was only 300 yen per game and postage was free if you spent over 5000 yen. On the flip side, Suruga-ya's prices for higher end games are pretty high. Good luck getting a decent response from FJ if something goes wrong.
I'm wary of any that ask for a deposit these days after ShoppingMallJapan went bump and nicked my $90 deposit. I'd personally avoid these unless anyone knows of any that are decent they trust.