Just try both games, play wichever you enjoy better and feel a bigger drive to improve with. Don't call for opinions on a site like this, it is 90% a bad idea as everyone is biased on some level or another.
Now do the following, play both games and try them out for a respectable amount of time. After getting the general feeling of both games, go ahead and watch some top level matches for both AS WELL as high level ones(not only people in top 8, go down to top 32 and top 64 or even waaay lower too FOR BOTH games so you can see what to expect in all ''above decent'' levels of play in both games.)
After doing all that, judge everything from both an SPECTATOR view and a PLAYER view and think to yourself :
*Wich game is more fun to play.
*Wich game do I like watching more.
*Wich game do I feel better improving at and defeating people at.
*Wich game would I prefer being watched while playing.
*Wich game speed goes better with me.
*Wich game would have me perform more consistenly in.
After that just let your preferences pave the way, it all comes down to trying both and how you feel about them.
I started out HATING Sm4sh in comparison to Melee and 64 but as I kept playing and understanding the game better it really grew on me to the point where I prefer playing Sm4sh competitively while Melee I enjoy more casually! And I ADORE watching any tournament play in both games.
But that's me. You can love one and hate the other, or even play both! but again I MUST stress that you don't look for too many opinions and search for your own conclusions. The internet gives way too much space for unconsequential criticism and uninformed arguments from both the sm4sh/melee side and it isn't healthy for newcomers.
Wichever you end up preferring it's absolutely fine c:
Vardamas