I actually hate Gundam W, but its worth it for being knowladgable about Gundam, so I hope to get a good discussion about the 3 protagonists of the AC universe.
First off, try to be reasonable. This is a purely "technical" thing, meaning all random Heero fans who have no idea of gundam should probably stay the heck out of here.
Heero in Wing Gundam Zero (Endless Waltz Version):
The reason I took the EW version was because, well, it has more power output than the series version. Also, Neo-Bird mode prolly won't do any good, leave alone work at all if either the buster rifle or the shield is gone.
Pilot: Heero Yui
Enhancing Systems: ZERO System (1.0)
Significant Features: 2 x Wings (serves as eyecandy and AMBAC system)
-Twin Buster Rifle, can be split up.
Wing Gundam Zero features a TBR with unmatched firepower and the ZERO system, whic continuously calculates all possible actions, outcomes and possibilities while forcing the information into the pilot's mind. This does NOT mean it lets you fight perfectly as you probably hear from uninformed amateur musers, because regardless of how you can deal with the information overflow, you can't really react to the mass of data properly, though experience lets you take plausible options. Heero is probably the most well trained pilot among the 3 due to his past of rigorous drillage. Anyone who watched Gundam W gets an idea of it. Heero is one of the few people who can use the ZERO system without going nuts, but he'd rather rely on his own skill as similiar to Zechs, he doesn't really like it when the system spazzes out and condradicts. He is also very mission obsessed and is more likely to sacrifice himself (though he sucks at self destructing).
Tiel in Wing Gundam Seraphim:
The successor of Wing Gundam Zero, lol @ anyone who said "Wing Gundam Zero is the strongest" before. Seraphim corrects the flawed 2 Wing design of Wing Gundam Zero which was kinda disadvantageous in terms of Mobility (bet you didn't know that). It also has a better ZERO system.
Pilot: Tiel Noembreux
Enhancing Systems: ZERO system 2.5
Significant Features: 4 x Wings
Wing Gundam Seraphim only has a single Buster Rifle, but much better mobility as one of the flaws of its predecessor was fixed. The original ZERO system was only limited in use as most people can't handle it, while those who could often preferred not to because the vague urges and hallucinations were very annoying when the system condraticts itself or the intentions of the pilot's strategy. Its successor ZERO system 2.0 fixed the problem by simply *forcing* the pilot to act accordingly, which unfortunately resulted to what happened to Tiel's brother. ZERO system 2.5 fixes the problem yet again by completely leaving out the pilot's mind (so nobody goes nuts anymore) and leaving it all to the system's AI, meaning the machine truely acts the way its ZERO system thinks is best to achieve what the pilot wants. Tiel is a civilian, so by far the most inexperienced pilot in here, its all the Gundam making up for her.
Odin (/Adin) in Gundam Griepe:
The pride of MO-V, Odin's unit is quite different from the other 2 as it was built by someone else etc., but its still made of Gundanium.
Pilot: Odin Barnett
Enhancing Systems: PX System
Significant Features: MA mode, Anti-Beam Reflector Shields
-Buster Mega Particle Cannon
First off, The Gundam here beats the other 2 in terms of thruster and power output by a whole digit (translation: its faster), apparently Dr. Berg pWned Dr. J and co. in terms of mecha building genius. It has 2 Reflector Shields over the shoulders (which automatically cover when in MA mode) which can take a direct hit from a Buster Rifle and remain intact, though it will eventually wear down. The PX system enhances the pilot both Physically and Mentally, (puts body into a high performance state, vaguely similiar to SEED mode). Odin is MO-V's test pilot, which is something (better than just being civilian at least, but he isn't some perfect soldier and rather flawful in combat, as shown in mock battles against his brother). He is talented though, and is one of very few people who can do a PX overcharge, meaning that he can push the PX system to enhance himself even more.
Basically, its a match between Pilot skill, Technology and Gundam Power among the AC universe. While Heero is the most experienced pilot and has a more ridiculous amount of plot armor, Tiel has the ZERO system 2.5 to act for her and Odin's unit is stronger in both speed and defense, while also shining offensively.