We all know that there are occasional holes in episodes, a few bits of luck on Columbo's part for clues found, and some things you just have to overlook and go with it. But what episode do you think is:

1) most realistic, as in it's most likely to mimic what might be a logical scenario in real life as to why the murderer did it, and how they did it

2) the murderer most likely to have gotten away with it

Looking forward to everyone's thoughts...

Most realistic murder-Blueprint for Murder

Most likely to get away- The Most Crucial Game

I have one possible one for "Most likely to get away" -

Even if she hadn't gotten off the OTHER way, maybe Grace Wheeler. After all, it was one of those "locked door" murders, so the suicide verdict must have looked pretty good to everyone but Columbo.
The irony is, she wouldn't have been able to enjoy it for very long.

The killing in Death Lends A Hand is unfortunately realistic: A man striking a woman in anger and killing her. There are other accidental killings like in Lovely But Lethal but Hand also shows how bad the killer's temper is.

It also falls into the second category in a way. If only he hadn't taken the bait and gone searching through that trunk late at night they might never have caught him.

My initial reaction is that the most realistic murder--if this one counts, because she is dead before the episode begins--is Hugh Caldwell killing his wife in a fit of rage with respect to "A Friend in Deed". Spur of the moment domestic violence is unfortunately all too realistic.

Perhaps the most likely to have not been caught is Dr. Barry Mayfield (Leonard Nimoy) in "A Stitch in Crime". It took Columbo himself a little more time to assess the final clue using his expert powers of observation.

I agree Collier might have been acquitted had he gone to trial. Trying to protect a woman from a pretty good beating and the killing was only the result of one blow. Instead of making the false burglary alibi he should have just
fessed up to the authorities. Only witness was the woman who was getting pummeled.

In response to Grant, I'm sure you've noticed how The writers of Columbo cleverly follow-up a "heat of passion murder" with a more calculated one.
It seems when they write the initial murder they say 'well this does not make the murder appear to be a dastardly person". We have to show the murderer is a cold worthless human being. Deadly State of Mind is such an example.
Other examples are:
Dagger of the Mind
Lovely but Lethal

It is interesting to note that the first heat of passion murder(or involuntary manslaughter) was in Death lends a Hand. I wonder if the writers realized that Brimmer was not that evil a person and they had to change things up to make the murderers more despicable.

I know just what you mean about those examples. It's interesting that Brimmer didn't really try to frame Ken the golf pro, let alone do it in the big way that Dr. Mayfield framed Harry Alexander. And as you say, maybe the writers realized their "mistake" in not making him commit any deliberate killing.

Brimmer was an unscrupulous person. He was virtually blackmailing people that he investigated. Plus he had a horrible temper. Not quite a cold-blooded murderer but at least not a sympathetic character.

First impression makes the Brimmer murder look almost accidental, but it wasn't as much of an accident as it appeared. He kicked the door shut, grabbed her very aggressively and said "I can't let you do that" then slammed her into the wall, when she pushed him away he punched her in the face and she fell into the glass table. Whether he lost his temper or not he was not going to let her ruin him.

Had she not fallen and died what could he do next anyway, once he grabbed her and punched her it was way to late to fix anything with her, his only choice would have been to kill her or have his life ruined.

Yeah, that's a really good point. Although it was an accident, if he had roughed her up, threatened her and then let her go, she'd be even more inclined to ruin his life and business through her husband.