Learn English – This is the first movie without excitement I’ve ever watched/I watched (I am not sure which is the accurate one)

In American English, "the same" is most idiomatic.

Yesterday, I talked about its and it’s, two words that sound exactly the same way but...

They sound the same way. The manner in which they perform the act of sounding is the same. Their method of sounding is the same. This construction emphasizes the procedure by introducing the noun 'way' into the sentence.

Yesterday, I talked about its and it’s, two words that sound exactly in the same way but...

"In the same way" emphasizes the mechanics of sounding. Two specific species of insects, for example, might produce sound through mechanically identical processes. "In exactly the same way" is more idiomatic than 'exactly in...'

Yesterday, I talked about its and it’s, two words that sound exactly the same but...

The same in its simplest form. Their sound is identical. This is the most common and generally applicable form. In this sentence, and indeed most situations, I would recommend this construction over the others. In the very specific circumstances that the added nuances of the above constructions are desired, then and only then would I advise their use.

As with many uses of perfect constructions in English, the difference is not in grammaticality, or in the objective events describe, but in how the speaker is choosing to relate those events in time.

If the speaker says I had ever watched, they are implicitly setting a temporal focus at a point in the past, from which they are looking backwards. If the say I ever watched they are not doing so: they are not setting any particular temporal focus.

In this case there is an explicit temporal focus in the past, the time when they watched The Dark Knight, so there is very little difference between the two. But in other cases there might be more difference.