For the horseback kill you can easily get your answer in the achievement guide & roadmap.
As for experience, I suggest the room with 17 small spiders in the lost city next to the Ashland. With War's Glory enhancement you can level up weapons without spending too much time.
All my played games are exactly 1000G! I'm a 1000G completionist.
I hate DLC achievements, since they always ruin my 100% 1000G record.
10000G for 10 games on 7/12/2010
20000G for 20 games on 9/8/2011
30000G for 30 games on 6/5/2012
40000G for 40 games on 24/9/2012
50000G for 50 games on 19/5/2013
Last edited by ImaginaryRuins; 08-10-2012 at 10:25 AM.