Taking a quick break from the magic lores to spice things up a little bit.
Blade of Realities:
This is a fun item with all sorts of uses. Put it on an oldblood and watch your opponent sweat. It is actually less good in 8th edition now that a BSB can let you reroll all failed leadership tests.
Blade of Revered Tzunki:
You can only give this to an Oldblood for 6 strength but for 5 points less you can give him the Giant Blade that has the same end result.
Giant Blade:
This is probably a little over kill on a guy who is already strength 5. Strength 8 is nice if you know you're going to be facing monsters. I'm not sure you need that much strength in general though.
Sword of Bloodshed:
Excellent weapon. Scimitar of the Sun Resplendent was a 7th edition favorite of mine and for just 10 more points you can give your Oldblood an extra attack. Pair this with maiming shield and enjoy a whopping 9 attacks. Add the Potion of Foolhardiness and enjoy a breathtaking 10 S6 attacks on the charge.
Obsidian Blade:
Not really worth it. I'm not a fan of negating armour saves unless it comes from strength.
Scimitar of the Sun Resplendent:
A 7th edition staple made obsolete by the Sword of Strife.
Stegadon War-spear:
Fun item. I don't know that it's good but you can guarantee that stegadon is going to mess up whatever it charges.
Ogre Blade:
You probably don't need much more strength than this so I recommend it over the Giant Blade. It is too pricey for skink chief or scar veteran and there are better options for an oldblood.
Sword Of Strife:
Scimitar of the Sun Resplendent but cheaper. Nice item when you want to get some defense on your oldblood or want a killy scar veteran.
Fencer's Blades:
This is more of a defensive item than an offensive item and there are better defensive items out there. I don't really like it much. Though I do find the idea of pairing this up with Glittering Scales and Aura of Quetzl to make a virtually unhittable character very humorous.
Staff of the Lost Sun:
I could see it being useful on a Skink Chief in a unit of Terradon riders but it would make the unit a little too expensive for how fragile it is. Very situational and opponent dependent. Putting him in a unit of skirmishers would be throwing him away.
Piranha Blade:
It has some uses but I personally wouldn't take it. There are more versatile options out there and you have better ways of dealing with nasty monsters.
Sword of Anti-Heroes:
I don't really see a situation where this buys you much. At best you're going to get +1 strength, +1 attack out of it but only when fighting characters. It gets you nothing against monsters or elite units.
Spellthieving Sword:
I would never take it. If you're hitting a spellcaster, you're probably killing him. There are of course exceptions worth considering (daemons, warriors, vampire counts, etc.).
Sword of Swift Slaying:
If you want to attack first, take the Lore of Light on a slann. It'll go much further. There are much better items.
Dagger of Sotek:
I don't see many reasons to take a Skink Chief let alone equip him with this.
Sword of the Hornet:
Exact same as the Sword of Swift Slaying above.
Sword of Battle:
Very basic. Good for a cheap magic weapon.
Berserker Sword:
Makes a unit immune to psychology. You're lizardmen so you aren't really worried about psychology though.
Sword of Might:
Very basic. Good for a cheap magic weapon.
Burning Blade of Chotec:
I like this. Gives a cheap hero a way to deal with regen and armour. Toss on something like a cheap scar veteran and stick him in an infantry unit. Gives bonuses for assaulting buildings and dealing with cavalry/war beasts for an extra perk.
Gold Sigil Sword:
Much like the Sword of Swift Slaying, there are better ways to strike first if you want to.
Sword of Striking:
Let's you hit on 2s instead of 3s. Nothing really special though synergy with lore of light for I10 and ASF is fun to think about.
Biting Blade:
Ewwww.
Relic Sword:
You're already doing this unless you're beating on a steam tank or you're a skink chief. Not much point.
Shrieking Blade:
Fear isn't that fantastic any more and there are other ways to get it. Take a real weapon.
Tormentor Sword:
If you're beating on a guy, he's already in combat and this isn't going to do much unless he kills you.
Warrior Bane:
What I said for Tormentor Sword.
There's a lot of cool items to pick from and I'd love to try some of them out. You can make some truly terrifying Oldbloods with these. Unfortunately, I love my slann and rarely get to try some of the awesome weapons as a result. My biggest Fantasy regret might be not getting a chance to try out Blade of Realities under 7th edition! Though I can't wait to field a Sword of Bloodshed Oldblood some time.