I personally never use melee too much. My big leagues is only rank 1. while other perks related to firearms like rifleman, commando, gun nut, science etc are rank 3. Currently lvl 39. I'll up all these to the max in the 40s. I use explosives a lot so I also have 2 ranks in explosives. Lockpicking and hacker are also very useful and i have 3 ranks in each. Investing in sneak you can be a sniper and take out targets from a distance with a decent suppressed sniper rifle. Otherwise I haven't looked at other perks that much. Initially I only choose those which are essential to combat and survival