Courses- If quantity it TW. Quality its WGT. To me I would favor WGT in this by just a hair. WGT courses are great but there are only 4 we can play. Tiger Woods courses are much lower quality but many more of them. Edge still to WGT.
Gameplay-WGT in a landslide. Tiger Woods games look like they are still being developed in 1999. Look at a Madden or NCAA Football game. The graphics are great. The TW guys don't put the effort into the gameplay. Putting is much better on WGT. Putting averages reflect more real life averages.
Community- WGT. The forums are more active on WGT in my opinion. Plus -28 at TW is 50845th place. Most WGT players are kind and respectful. Also, the mods. I may not agree with what they say, but at least they say something. They assure me they care. Over at EA Sports, there is a 20 page thread about a big issue in this years NCAA Football game. Not one mod has posted on that thread. Most likely the same on the TW series. Same company. It makes assuring to know that my suggestion is noted. Doesn't need to be put into play, just noticed.
Clubs- Edge goes to TW. They have more clubs. Cobras are something I would love to have here. Also, they have name brand golf balls. The effect of the clubs is great here but would still like the selection at Tiger Woods.
I did not buy the Tiger Woods game this year because I have more fun playing on WGT. I used to buy the TW games for the 360 but those days are over thanks to WGT. I really enjoy playing this game. Keep up the work WGT.