For the simple answer I'll mirror my settings w/ brief explanations. I run a AMD R9 280X 4GB edition
1. Anti-Aliasing
AA Mode - Override Application Settings (Let your hardware pick apart sampling)
AA Samplies - None
Filter - Edge Detect (Get rid of jagged edges)
AA Method - Supersampling (It's really the best way to AA)
* note: Multisample is best for performance, worst on image quality. Adaptive is middle of the road, tends not to make much of a diff in SL compared to Multi. Super is best quality, worst performance... You can play around with these.
Morph Filtering - OFF
2. Texture Filtering
Anisotropic Filtering Mode = Use app settings
Anisotropic Level = n/a
Texture Filtering Quality = High Quality
Surface Format Optimization = On
Give those a try, like I said they're what I use and use with a pretty swift computer / connection.