Hmmm.... All your pokemon look amazing making it hard to choose. I'd say Raikou and Zapdos since Kyogue is coming out soon. One of your Machamps depending on which one has a 15 attack stat and a decent defense stat. Maybe after that your Tyranitar in case you get a Mewtwo EX Raid Pass. In terms of levels maybe get your Raikou up to around 2600 CP and your Zapdos to around 2800 CP. Tyranitar needs to be over 3000 CP.
Power up priorities
These are the Pokemon that I'm planning to power up soon. Which ones should I prioritise, and what level should I power them to?
If this affects anything, I have a self imposed rule of not powering multiples of the same legendary with the same moveset.
1: Dragonite 96% 141415 DT/O
Now at L32, CP 3202. I have other Dragonites at L30.5, DT/O, L31 DB/H, L30 DB/DC.
2: Ttar 96% 141514 B/Cr
Now at L28, CP 2918. I already have 2 B/Cr Ttars at L32 and L30, both below 90% IV.
3: Ttar 93% 151314 B/SE
Now at L22, CP 2291. I already have 1 B/SE Ttar at L30, 91% with 15 attack.
Geodudes are rare in my area.
4: Raikou 91% 151313 TS/WC
Now at L24, CP 2273.
My only Raikou, I transferred the rest away because they were all below 82%.
I only started powering this Raikou up last week. The powerup was long overdue.
5: Zapdos 98% 151415 CB/Tb
Now at L27, CP 2564. My team bird. I powered him at least a month before Raikou came to my continent.
6: Machamp 93% 151215 C/DP
Now at L30, CP 2455. Caught and evolved from a Machop nest, my first ever fast TM recipient.
I have another Machamp at L29 and a Hariyama at L33. Both have IVs in the 60-80 range, and C/DP.
Also another Machamp at L20.
7: Machamp 96% 151414 C/DP
Now at L20.5, CP 1683. Accidentally powered it up once.
8: Entei 98% 151514 FF/Ft
Now at L20, CP 1926. I have quite a few Flareons at L30 and above.
Answers
Prioritize Dragonite, Machamp and Raikou. They're the ones with most general utility, meaning both gym and raid performance. Power up Tyranitars if you care about Alakazam solos or get an EX invite.
Everything you listed is well worth powering up eventually. Zapdos gains priority when Kyogre raids start and same is true for Entei and Registeel/Regice raids.
Raikou and Zapdos will be the most useful in a couple weeks. I have one Zapdos at 40 1 raikou at 40 and 1 raikou I'm working on that's at 33 34 I'm trying to max to 40. Entei will be very useful for gen3 legendary raids. Jirachi, celebi, registeel, regice for legendaries. Metagross will also be weak to entei also. I maxed out 2 entei to 40. I have the same entei u have and a 100iv one too. That one is 3370cp at level 40. My perfect is 3377cp at 40. Max them out, no reason to stop at 30. Charge moves will scale all the way and taking charge moves will scale too. I noticed a big difference from my 2 raikous. The level 40 would survive the fight way longer and dished out way more damage.