How are you playing a G Chord? Watch the video...
I am not talking about the different voicings of G, like G+5, G bar chords or G power chords. This is stock standard G!
There is no right or wrong way to finger any chord. It depends on how it is being used in the songs. But choosing the best way will help your playing.
Using fingers 123 - These are your stronger fingers. This fingering is easier to learn.
Using fingers 234 - Initially it is harder to get your fourth finger to work. The big advantage of this chord is changing to C chord. The shape of both chords are similar making for a quicker, smoother change. Practise changing just the top of the chord.
Also, playing a Gsus4 and G6sus4 is possible using this fingering - your first finger is free to use.
The answer? Learn both. It will make you a more versatile player.