I think a James Bond actor needs a gravitas both of those guys lack. Connery certainly had it. Craig certainly had it. The rest were a bit meh.
I think Idris Elba has it too but, considering what others have said, I agree he is now too old for the role. (He could probably mange to get one movie out but I am sure they want more movies from the next Bond.)
Henry Cavill? No, also too old.
I haven’t seen a ton of Aaron Taylor Johnson, but I really don’t like him for the role. Jack Lowden I think would be good. I liked him in Slow Horses, and the role isn’t the same, but he works in the espionage genre.
To me, Roger Moore did his signature schtick just fine, because, well, (a) to whatever extent that he’s supposed to be a secret agent, he can display a lack of gravitas instead of flashing a ‘danger’ signal at people like Connery or Craig; and (b) when the mask does come off — when he’s past the need for superficial charm, and he’s in a situation where it’d be appropriate for a normal person to show some gravitas — we get reminded that the cold-blooded guy who kills with a shrug can easily remain calm in between being, what, lightly amused?
No, really: if you wanted someone to portray a sociopath who makes a living by passing himself off as a warm and gentlemanly sort who means you no harm, one could even say that nobody does it better.
I get that. Good one! 
FWIW Moore is my third favorite Bond. (Connery #1 and Craig #2…and that’s a close one…I could put Craig as #1 except I grew up on Connery so there is that nostalgia.)
He doesn’t seem too old and, I’d think, a pretty good choice.
His major downside is he is not British. Would they ever consider a non-British actor for the Bond role?
Yeah, but he’s not going to scare the living daylights out of anyone.
Stranger
Ok, you genuinely had me. I had to actually go double-check.
Doh! I saw “Jersey”. My bad. He is British. 
I’m embarrassed.
In that case I think he should be on a very short list for the next Bond actor.
Wait, people liked Roger Moore!?
I guess they must have since he starred in the most films (tied). but damn are they bad.
I’d go 1) Connery 2) Craig 3) Dalton 4) Brosnan 5) Moore
I don’t believe I’ve seen the Niven or Lazenby movies. Brosnan only has one good movies, but he’s the one I grew up with and the Goldeneye video game parties were formative so he’s above Moore for that.
Roger Moore was really great in For Your Eyes Only where he actually played Bond as more of a coldly calculating killer, and there is even an argument to be made for him in Octopussy (as bad as that film is otherwise). Moore had more acting chops than the material generally allowed for, but arguably had the weakest run of films that hewed toward foppishness and gadgetry. Dalton was probably the closest to Fleming’s literary portrayal, although Craig certainly played it straight in Casino Royale and Quantum of Solace before the off-brand Archer hackestry that was Skyfall and the nonsense that followed.
Connery really had two good films—Dr. No and From Russia With Love—before the movies started becoming more self-parodies of an inept drunkard propped up by Q branch, but Lazenby really did quite well in his only film for having virtually no acting experience (aided by Diana Rigg, Gabriele Ferzetti, and Telly Savalas). Brosnan was always playing a pastiche even though he’s actually quite a good actor, and he does a great job of subverting Bond tropes in The Tailor of Panama or playing a criminal version of Bond in the remake of The Thomas Crown Affair.
Stranger
I think Connery had 3 good films, Goldfinger being the third. However, it’s a different genre than From Russia with Love and mostly carried through until Casino Royale. Were the kitschy films well received in their time and have just aged poorly, or were they always bad?
I honestly think this is the first time I have heard anyone speak well of Lazenby and Bond. Almost always he is put at the bottom of the Bond list.
The only reason he is not forgettable to me is that he is the one who is forgettable. So, weirdly, I remember him.
Goldfinger was certainly a template for the Bond franchise but if you look at it with a critical eye, Bond essentially ‘fails forward’ at every turn, from being repeatedly knocked out, captured, failing to get a message out or escape despite all of his gadgets, and getting both of the Masterson sisters killed pointlessly, he doesn’t even disarm the bomb, instead clutching helplessly at wiring until a technician interrupts to turn a switch. The only thing Bond does right in the entire film is to cheat at golf better than Goldfinger and rape Pussy Galore out of her lesbianism, although frankly some criticism should be levied at Felix Leighter and the CIA for not uncovering a plot to smuggle Chinese nuclear bomb components into the country using the Mafia.
Dame Diana Rigg has said that his acting was “really quite good” even though he was problematic in his off-screen behavior. On Her Majesty’s Secret Service is widely regarded among film enthusiasts as one of the more innovative and distinctive Bond films even though it underperformed to expectations following the exaggerated antics and so-bad-it-is-comical ‘yellowface’ of Connery in You Only Live Twice.
Stranger
Bond sleeps with 3 women in Majesty’s during a run time of, what, 135 minutes? Seems like Lazenby had to tone down the womanising a little to fit that, if the stories are true. He fully admits it himself to be fair. I’ve seen the documentary on his rise to stardom and the Bond role and it’s not for the faint hearted, although he didn’t come out of it as a total arse, in fact I felt a bit sorry for him to be honest.
Given that Jack Lowden’s most recent appearance on British TV was his highly acclaimed turn as notorious psychopath happy-go-lucky geezer, Kenneth Noye, the one thing he doesn’t lack is the necessary heft.
I’ll be happy to be surprised.
Never in a million years would I have guessed Heath Ledger could play “The Joker” but he did and nailed it.
Maybe Lowden can deliver. It’d be really great to see if he pulled it off.