It seems like College of Swords is a viable edition to the "gish in a box" options for d&d 5e.
Collage of swords is a slightly more offensive than valor. But blade flourishes don't work with booming blade and eat up your inspiration dice, which still requires Cha.
So not great.
Oddly it works with bows. Might be an oversight.
Hexblade looks like its going to be a very common dip for bards, sorcerers and paladins.
Armor, shield, Cha to hit, and booming blade for a 1 level dip really opens up some doors, including making collage of swords or valor a lot less MAD.
You can also get Cha to attack with bows via blade pact + improved pact weapon. And get your smite without going paladin.
But yea, hexblades have armour, can blast at range, hit in melee, and have a bunch of spells. Probably the top gish without multi-classing.
At high enough level any wizard can cast tensers transformation to become an instant gish.
It's concentration, and while it does give you proficiency in Con, advantage, and good damage (2 attacks with +2d12), it doesn't give you any Dex/Str and can give you exhaustion.
So I don't think it's something you want to depend on.
Sorceror's get Shadow Blade and Absorb Elements now, so even a clever start up Sorceror can do at least some Gish stuff. (Summon Shadow Blade, take fire/cold/acid/thunder/lightening damage, cast absorb elements as a reaction, gaining resistance to that damage type, then unleash it in you mext melee attack).
That and darkness+devils sight for 2 SP, giving advantage on all attacks.
Though it still seems better for multi-classing then a straight gish.
Divine Souls also get access to Holy Weapon, although unlike other Sorceror's Divine Soul's are divine spell casters, so I don't really count them as gishes. Still a EK fighter 5, Divine Soul 15 makes an interesting alternative to a Paladin.
Divine soul doesn't get any martial abilities. It just adds heal spells (and wings at 14).
War wizards seem much better for dipping, and can share EK's Int.
There might also be some fun with storm sorcerer/paladin flying around with booming blade + thunderous smite.