I'm sure there's several, but that doesn't mean it might not still be the best card for you

It's all going to depend on why you want the Ultimate Rewards (UR) points. What's the driving factor to wanting those particular points? And ultimately, what's your overall goal for credit card rewards?
The Freedom cards (plain Freedom aka CF, and Freedom Unlimited, CFU) both earn UR points that can be redeemed for 1 cent per point - either as cash, a statement credit, or used through the Chase travel portal. You can also redeem them for gift cards and products for 1 cpp or less, but that's hardly ever as good value so I just ignore those for now. Both have no annual fee so when choosing one over the other you'd want to look into the earning potential of each. (Ideally you'd want both, but we'll hold off on that for now)
The CFU is an easy calculation as it gets 1.5% back on every purchase plus the sign up bonus. I'm seeing $150 (15,000 URs) back on $500 in spend, is the $200 bonus still floating around? I'm going to stick with $150 for apples to apples for now. I'm going to throw out a round number of 10k of annual spend planned for the card. That'd be
$300 back in the first year, $150 for the sign up bonus and $150 in UR points from the spend.
The CF has the 5% rotating categories each quarter, up to $1,500 spent (max $75 back per quarter) and 1% back on everything else. It also has a $150 (15,000 UR) sign up bonus for $500 in spend. Assuming you can max out the categories every quarter, for the same 10k in spend, that'd be
$490 - $150 for the sign up bonus, $300 for the category spend, and $40 for the remainder. I imagine you can't always max out every category (I rarely do) so I'll also make an assumption only 20% of that spend is at the 5% level. That still
$330 - $150 bonus, $100 category spend, and $80 for the remainder - edging out the CFU by $30.
So what would be better than that is instead of putting the non category spend on the CF card you put that on the CFU card for the extra .5%, best of both worlds.
But, assuming you have the 10,000 in spend to put on these cards, if you are able to do higher amounts within 3 months you could be looking at even larger UR points. The Sapphire Preferred card does have an annual fee but it's waived the first year. After the first year you could product change it to one of the Freedom cards and still have no annual fee. For the $4,000 in spend within 3 months you'd get 50,000 UR points, the equivalent to $500 in cash. It earns 2x the points on dining and travel charges. It's not the greatest for ongoing spend unless you eat out a lot or have things that code as travel, but just the sign up bonus is usually worth getting this card. The Sapphire cards also allow you to transfer your UR points to travel partners, like hotels and airlines, and give you a greater redemption value through the Chase travel portal of 1.25 cpp. If you thought you'd like to use the UR points for either of these things, then it may make more sense to try for one of these cards even with the annual fee. Which is why I wondered what drew you to UR points versus another points system