BBTS Seacons. Why? because their a combiner that friggin splits into piranha's and octopuses, what not to love?
Instead of spamming up the topic, please use the report button to request a move. Anyways, go with the Seacons. I don't have any of those toys, but those would be the ones I'd buy if given those choices.
Only one I have is the Seacons, but have seen the F/R pack, and it is pretty damn impressive. It will be one of my next buys if I have some spare cash. I am not into Alternity, and I don't like the bellies on the BB/Cliffy mold to boot, so that one is out for me.
I desire bts-03 that is my next and only next transformers purchase.. from your list i would say the seacons, i love me some combiners.
Depends on your preference. It would be good to get Seacons while they are at retail price before the price goes up. Frenzy and Rumble have some QC issues. They do display awesome with music label Soundwave.
Depends on what you collect more of. If your collection is mostly classics based, get the PE's. If you're ALT/BT/MP based get CJ, and ditto for Seacons and G1. I have all three of your options, the PE's are coolest but you get the least amount of toy for your money with them. CJ is pretty awesome, and probably the best buy for the money if you shop around.
My vote is for the Shadow Warriors. They'r pretty expensive for how big they are but they're great. Seacons are ok, but personally I'd rather have something modern. That's just me. Alternity Cliffjumper is alright. the ead sculpt is really cool but the body just looks like random cut up pieces of metal. It's a neast display piece but if you want something to fiddle with I recommend staying the hell away from any of the Alternities. Granted everything above should be taken with a grain of salt since they're MY opinions and may or may not line up with your tastes or collecting habits