GT6 is better, but I'm missing some things from GT5.
GT5
- Shuffle Racing
- Course Maker
- Better photomode locations
- Top Gear Test Track
- Car trading / sharing
- Ferrari F1
-custom one-make races with standing starts, mechanical damage & fuel/tire wear
-arcade races with normal rolling starts, 16-car grid, mechanical damage & fuel/tire wear.
It's really odd how GT6 has more cars & tracks than GT5 but it doesn't have proper racing offline.