Here's a summary of my random Shepard. Had to check most from memory and Gibbed save editor since it was a while when I did this.
In no particular order:
Infiltrator, Spacer, Survivor. Singularity bonus power.
Talked to Barla Von without knowing he was an agent for the Shadow Broker. Didn't really add any different dialogue.
Helped Rita and Jenna.
Went all Paragon on Conrad Verner.
Let Fist live.
Scared away Chorban and helped Jahleed scan the keepers. Jahleed will go back to work properly.
Council got saved.
Chose Udina.
Agreed to help Schells with the quasar game, gave the device back to him.
Toombs and scientist both went to trial.
Never hang up on the Council.
Helped Kahoku find his men, then located a dead Kahoku.
Gave Geth data to Tali.
Rana Thanoptis didn't outrun Shepard's bullet.
No romance.
Shepard thought it was a waste of time to hunt down Dr. Heart for Garrus.
Also couldn't be bothered with Wrex's armor.
Kirrahe survived.
Kaidan picked the survivor card.
Rogue VI completed.
Let the Rachni Queen live.
Shepard really wanted to find all 16 asari matriarch writings.
Bought Elkoss Combine license.
Told Michael & Rebekah to get the gene therapy.
Balak left while Shepard saved the hostages.
Zhu's Hope and Shiala survived with a few casualties.
Spoke to mom, told Zabaleta to go to the VAO.
Gave Emily Wong the data from Fist, then told her not to spy on Traffic controls.
Let the Alliance keep Nirali Bhatia's body.
Agreed to help Gianna Parasini, and convinced Lorik to help.
Chairman Burns died together with the terrorists.
Helped Sha'ira. Did not go to Eletania.
Told krogan to stop messing with Dr. Michel.
Accepted Helena Blake's money.
Killed Nassana's sister without speaking to Nassana first.
Never met Han Olar.
Gave Khalisah al-Jilani a decent interview.
Intimidated Ethan Jeong.
Told Keeler to get help with his drug addiction.
Major Kyle came along peacefully.
Convinced hanar Preacher to leave.
All in all it would seem like Shepard ended up fairly paragon without wasting too much time on saving the galaxy.