First let me say: Captain Kirk is one of my favorite characters in all of Trek. William Shatner I'm not so hot on, but here I'll try to explain why I don't want to see him as Kirk anymore... Take a look at some clips from TOS, or even a still shot. You'll see someone with the 'eye of the tiger' so-to-speak. A stern brow, rigid. This guy looks tough. He talks quickly and assertively (somewhat overblown dramatic pauses not withstanding). Now look at any of the later films or pics of Kirk from that period. You'll see eyes with a somewhat sarcastic nonchalance to them. They're relaxed, even comical. I'm not talking about wrinkles or age - that would be fine. I'm talking about they way he's holding them, his general attitude. Furthermore, listen to him talk. It's laid back and also easy-going, with a bit of ho-hum and whimsy to it. That's not Kirk - it's Shatner in a uniform. The man forgot how to play James Kirk a long time ago, or stopped trying. When did this happen? Well, he's definitely still got it in STII. The bottom eyelids are up, and he's got a snap to his delivery. Note how he turns his head and tells it to Dr. McCoy regarding "the dangers of reopening old wounds" in the turbolift. He also seems to still have it in STIII. In fact, his acting when David is killed is even better than in STII with Spock (althought the Spock death was better overall as a scene). That, while still keeping to the essence of Kirk - a difficult feat. Then in STIV is where we first see the slip. While IV was a great ride and a fun film, consider the alleged Kirk talking to Spock on the train (just after the punk rocker incident). Consider him in the "it's better for them/you" lines in Gillian's truck. That is not Kirk delivery. Here we're getting Shatner. Could this have to do with the change in directors to Nimoy? Perhaps. Can you imagine Nimoy trying to tell Shatner he's not playing Kirk right? Maybe Shatner thought the change was a good opportunity to do it how he liked - who knows. By the time V comes along we've got Shatner directing and the real Kirk has been fully buried. Sadly, we haven't seen Kirk since he answered Spock's "your name is Jim" at the end of STIII. Now, if there were some way to get around the complete cheesiness of yet again bringing back another character from the dead, we'd need to get an acting coach to completely re-train Shatner on how to play Kirk, as if he were jumping into the role of a historic figure, from scratch. But, alas, cheesy it would be so I'd rather look more to the future at this point.