Great hammers and UGS are favorite strength gear but consider this - If you go pure STR you will miss on 2/3 of DEX and quality gear. Interesting stuff like lances, halberds and twinblades. IMO with disappearance of lvl 150 meta there is no reason to limit yourself to STR alone - You could go with SM >5M /SL 200 "meta" (that I'm not sure if it exists anymore) for pvp interactions or just level without limitations.
At SL 200 (3-5M SM) you can make really tough quality build warrior 50/40 (you can even squeeze in 30 FAI and spice down SLB to 30 to buff your weapon) but ofc you could start with raising STR to 40 fast and stomp the PVE portion of game ASAP.
Probably best STR weapon that you will find early and it's good for whole game is classical "pizza shovel" UGS. That weapon is many ppl. favorite. Range, moveset and overall feeling of badassery. Only downside is weight.
Of ultra hammers drakekeepers is decent and kinda balanced. Giant warrior club /smelter hammer if you want to push STR build to extremes, and for more balanced earlier PvE large/great club are good options. Versatile moveset, good damage type, very solid STR weapons.
OF UGSes, already mentioned plain GS, zweihander if you want high damage and good moveset UGS but with lower weight and requirements, dakewing, if you like the aesthetics and want missile damage, fume UGS /you want to try this one for sure, Ivory UGS (very badass DLC weapon) and crypt GS for dark+Dtr user but you must build your character around this weapon (I'm playing that build atm)
"Forgive me, all of you, for I have availed you nothing..."
Knight Artorias of Four