X-2 was a good game, but those "convenient" close-ups of Yuna's ass in those shorts were pretty obviously only done for the sole purpose of fanservice.
Actually it can be denied as there was more to the game than fanservice, as it had a plot and a purpose. A pure fanservice game would pretty much be a pointless game where the main focus is fanservice.
I figured you meant fanservice = sexy stuff involving the girls
fanservice is something that caters to the fan's main interests. So if they want sexy stuff, they get sexy stuff. If they want a person X person they get person X person.