Yes, he was. Without going into Caesar's entire career (which would be an absurdly massive undertaking that is simply impossible given the constraints of reddit), Caesar was an extremely talented and intelligent person, and it's quite clear from his behavior, his reputation, and his own writings. Now, it's very easy to fanboy about Caesar--the man had lots of flaws, made mistakes just like every other person, and had a somewhat...twisted sense of morality (Badian pointed out that many of his pronouncements and actions reek of sociopathy). Nevertheless, even his most prominent critics, ancient and modern, unanimously admit that Caesar was both brilliant and talented--the great Ciceronian scholar and staunch anti-Caesarian Shackleton Bailey was forced to admit that Caesar was supremely talented, claiming that it rubbed off on everything he did. His translation of Cicero shows this admission:

Fuit in illo ingenium, ratio, memoria, litterae, cura, cogitatio, diligentia; res bello gesserat, quamvis rei publicae calamitosas, at tamen magnas; multos annos regnare meditatus, magno labore, magnis periculis, quod cogitarat effecerat

Caesar had talent, the ability to reason, a retentive memory, literary talent, concentration, reflection, industry. His military achievements, even though disastrous to the Republic, had been great. Aiming at monarchy for many years, he had accomplished his intention by means of hard work and great risks.

Those lines also attest to Cicero's fascination with Caesar--throughout his letters we see time and time again, almost every time that Caesar is mentioned, how totally entranced Cicero is by Caesar, even though he disagrees with him. Even Caesar's bitterest enemies have to admit that what he accomplished was great--terrible, perhaps, but nonetheless incredibly great.

If we're gonna list Caesar's accomplishments it must be understood that Caesar was not simply a military commander. There's this odd idea in popular culture that Caesar was simply a soldier and that bam, one day he fought the civil war and all of a sudden he was a statesman. That's rather the reverse of what happened--apart from his military tribunate (which in the late Republic stood for exactly nothing with respect to military experience) Caesar had no military experience before his proconsulship in Gaul, and he had never commanded an army before. Caesar was forty when he was elected consul, and forty-two when he went off the Gaul. Military command came rather late in life, and it was not a goal in and of itself--Caesar was not what Cicero calls a "vir militaris," essentially a career soldier (the term Cicero uses to describe the professional career officers that militarily inexperienced governors put on their staff as minor magistrates during their promagistracies--Cicero relied on them heavily in Cilicia). Caesar was a statesman, a politician beginning from his earliest youth. Politically what Caesar managed to do was nothing short of astounding--I mean, the guy became dictator for life! That's not an office that they just hand out to anybody. Caesar's political legislation was marvelous--he went from being hunted by Sulla's partisans to such a serious degree that he slept in a different bed each night of his youth and eventually fled to Asia to shoring up the vast political differences between the Pompeians and Marians and establishing what was undoubtedly the most politically revolutionary consulship of the Republic. Caesar's political maneuverings were indescribably impressive--he clawed his way up the cursus honorum (unlike Pompey, who used Sulla's influence to skip it entirely), championed Pompey's Eastern Settlement and land distributions, reconciled the supposedly irreconcilable Pompey and Crassus, got Pompey's Eastern Settlement and established the decemvirate (an act considered politically impossible--Pompey had tried to push that legislation through for a decade, and Caesar completely outmaneuvered his political opponents and forced it through), wormed his way past the senate's attempt to vote him promagistrate over the trees of Italy instead of giving him a province, extended his own proconsulship by five years to finish his work in Gaul (delaying Cato's prosecution), and while all the way in Gaul exercised enormous political influence, essentially holding the strings of Clodius' life and supporting Cicero's exile. Caesar's ambitions all lay in the political arena, and while it's debated whether his end goal was always to control the state (most scholars think that's nonsense) he still managed to do so, where countless others had failed. And he did so much more totally than Sulla had--even after his civil war Sulla had had to resort to the threat of force, which made enemies of even the most conservative politicians, whereas Caesar was notoriously generous and forgiving to his enemies, enacting no proscriptions. That's no small feat, no matter how morally reprehensible it may be (and yes, it is--Caesar was not a nice guy)