I know that there are too many question about the free 4 stars but I couldn´t help myself.
I have trouble choosing between:
the obvious BARSARKA Heracles, Tamamo and Martha.
I started playing FGO right after Saber Wars and got pretty lucky with my rolls so these are my lineup servants:
Brynhild, Waver, Amakusa Shirou, EMIYA(archer), Shiki(Assassin), Frankenstein, Caesar and Ushiwakamaru.
My problem is pretty much between utility and the epicness of Heracles.
Frankenstein is better than Tamamo and I rate Martha quite lowly(3*s hit harder than her until she gets her 2nd and 3rd strengthening quests which are quite far away and unless you specifically really need to remove debuffs/buffs I'd say Alexander is even a better support) so I'd say Heracles is your best option.
I'm an even newer player than you, but as far as my knowledge goes, the current Martha's pretty bad, she's like D'eon without the cool Taunt, and I've been substituting Tamamo pretty well using Kiyo, so I'd say go for Herc.
Epicness aside, he made the game so much easier for me.
