This is not an easy question to answer, as it is very open ended. In games like this, especially with a pvp, the -best- only exists for a particular playstyle. For example, if I wanted to build a dps cleric for pvp, damage-related feats would be better than healing feats, and if I wanted to build a healer, healing feats trump damage feats. The same applies to the tr. Are you wanting a perma-stealth build, a deflect/regen build, or a hyper burst build? Remember, feats and gear should be built around a playstyle, not the other way around.
If you want more of a burst/high damage tr, go down the executioner tree. Dazzling Blades for the first feat. The second feats don't really matter, put the points where you wish. Brutal Backstab for the third column. It's up to you if you want Deadly Momentum. That depends on if you will be using Duelist's Flurry in pvp. If not, get Critical Teamwork. Obviously grab the capstone feat, Overrun Crit. You should have 5 or 10 points left over. Where you spend these is completely up to your personal preference. Prefer to be in stealth? Go the top tree. Combat advantage? Middle tree. This is a basic skeleton that you could possibly change according to your preferences: http://nwcalc.com/tr?b=cn4:2hwcg:5m9s,1fi3i8i:60000:6u000:b0zz1&h=0
It's not even close to perfect, but I threw that together quickly.
Just remember, build your character around your play style. There are some very successful tr's out there with some very different feats.
Comments
If you are wanting permastealth/stealth-oriented fighting, see http://nw-forum.perfectworld.com/showthread.php?295232-Banelorne-s-Stealth-Based-Executioner-Builds-Maximize-Your-TR-s-Solo-Capabilities. This is a large guide dedicated to stealth-based play. Feats are listed there.
If you want more of a burst/high damage tr, go down the executioner tree. Dazzling Blades for the first feat. The second feats don't really matter, put the points where you wish. Brutal Backstab for the third column. It's up to you if you want Deadly Momentum. That depends on if you will be using Duelist's Flurry in pvp. If not, get Critical Teamwork. Obviously grab the capstone feat, Overrun Crit. You should have 5 or 10 points left over. Where you spend these is completely up to your personal preference. Prefer to be in stealth? Go the top tree. Combat advantage? Middle tree. This is a basic skeleton that you could possibly change according to your preferences: http://nwcalc.com/tr?b=cn4:2hwcg:5m9s,1fi3i8i:60000:6u000:b0zz1&h=0
It's not even close to perfect, but I threw that together quickly.
Just remember, build your character around your play style. There are some very successful tr's out there with some very different feats.