Talking about Star Trek Voyager, the voice actor for Kaidan Alenko was one crewman of proeminence during the first 2 seasons, the one who betrayed the crew along with Seska to the Kazon race.
But no one here should question Capt. Janeway´s competence. Trust me, you don´t want to see Morrigan´s mother angry.
I´m currently abou 2/3 done on a new ME3 play (using a ME2 character) and I did notice a few new things:
If you faced the rachni cloned breeder (the queen engendered by the reapers), when tali and garrus discuss all of the previous missions and foes the breeder will also receive a mention.
During Jacob´s rescue mission, if you take Edi along she will say that jacob did not recognize her on the new body. If you take Tali, she will offer him a much warmer reception than the one they had in ME2.
When Tali is recruited in ME2, she will have additional complaints about Cerberus when she is recruited if you did the side-missions, adding that the people at cerberus thought that enslaving rachni and thorian creepers was a good idea.
In ME2, depending on if you killed the asari who murdered the volus merchant or spared her and question her about morinth will affect conversations with samara slightly, since you already know the term ardat yakshi.
Admiral Haan will have different responses regarding the civilian fleet based on admiral korris remaining missing, being dead or having been rescued.
The introduction to the Geth Base (actually, a reaper) that happens on the war room as soon as Korris or Legions/VI´s mission is completed will also change based on if you saw the origin of the geth or if you decided to rescue korris and/or his crew.
If you took Legion in ME2 to the Quarian flotilla (tali´s loyalty mission) the quarian leadership will recognize him in ME3m by saying ("I see that your geth friend has returned"). Otherwise they will be in for a shock.
If you played ME2 dlc Lair of the Shadow Broker, the Illusive Man will reefer to Liara as Shadow Broker in ME3. Otherwise, even though Liara can specify in conversations that Cerberus was after her, he will simply call her a prothean expert.
Depending on Mordin or Padok being the inside source for the krogan leadership in ME3 about the female krogans immune to the genophage, the footage from the salarian base differs. One will come from security cameras. The other from a portable device. Omni tool probably.
A full paragon shepard would end up contributing to Javik´s and Kelly´s deaths. If he started later than me1 (rachni queen dead) he would also release the breeder and allow some dangerous people to run wild the recently-recruited eclipse mercenary in ME2, saren´s asari assistant, Vido from the blues suns, the batarian terrorist balak, the xenophobic turian Joram Talid, the gang-leader Helena Blake, the salarian and the volus who wanted to scan the keepers. I´m not gonna say darius because one needs to have a high renegade score for him to show up.
During the final segment of ME3 (cerberu´s base/crucible to earth) it is possible to cause the deaths of Legion, Jack, Morinth, Shepard, all of the squad-mates... And of course the mandatory deaths of Anderson, Ilusive Man and possibly Kai-leng (I could swear he was still moving).
I think this was mentioned already, but anyway... ME3 keeps track of who did what on me2´s suicide mission. If Tali was the one in the vents and/or jack generated the biotic bubble and they survive into me3 there will be mentions of it if you talk to jack at grisson academy or tali when they board the geth capital ship.
The side-quest in me3 with the sick batarian terrorist who begs to die will change depeding on if you did me2 dlc arrival or not.
If you did arrival, and took javik to the geth dreadnought shepard can mention the sacrifice he had to make with the batarian colony.
The brief intro section with the virmire survivor in ME3 is different based on whether you are using a brand new shepard or one imported from me2.
If the original council is alive in me3, joker will say he finds the asari representative attractive when edi is asking in purgatory about different women. It it´s the new councilor he has a less favorable opinion about her, complaining that she uses too much make-up.
if you have too many dlcs installed, you might lose this me2 scene. As soon as you obtain the normandy sr-2, go to your cabin, read all of your emails, except the one from anderson. then go to the second floor and walk by kelly. she will announce that a message from anderson is waiting. If you have an abudance of messages (specially the ones from DLCs), she will simply say that you have unread messages.