There are 1001 kind of bags... For us to recommend you, first tell us what is your gears, preference like shoulder/backpack, kind of outing that you'd bring out your gears, etc.
As for me, after using so many brands and type of bags I finally settled down with 7 bags now.
1. Tamrac Expedition 12 Backpack
2. Tenba Pro Traveller 695
3. Tenba P513 Briefcase Camera Bag
4. Billingham Hadley Pro Briefcase camera bag
5. National Geographic Medium Shoulder bag
6. EagleGreek Traveller pak w/Domke Inserts
7. LowePro Pro Roller I Case.