MP-05 Megatron is pretty terrible but I don't own it anymore so I'd say either Tracks or Smokescreen.

 

I've got a bunch, granted some aren't out yet.

MP Tracks (bot mode)
MP Ironhide/Ratchet (bot mode)
MP Hot Rod (bot mode)
MP-11 first run Takara Starscream (floppy mess)
MP Bumblebee (bot mode)
MP-5 Megs (bot more)
MP-9 Takara Rodimus Prime (fragile)

 

Except the scale, of course...  

Good point. The upcoming Ironhide, Ratchet and Hot Rod look far, far worse than any of the Masterpiece Transformers produced to date.  

 

Fucking seekers!!! Total trash! If having a seeker wasn't a necessity in a decepticon collection i would tie a m80 to that floppy pos.

 

Smokescreen wouldn't be such a big deal if they made a more toy accurate version of him. It totally frustrates me to see nine variations of silverstreak released that are all toy homage.

 

MP-5 / MP-9 both are really bad.

 

I kinda like Smokescreen but a few things about him bother me. He's got racing ground effects but stock wheels which looks stupid as fuck, also the lack of more racing decals bothers me for some reason.

 

The ground effects are great, that detail is in the original car, toy, and cartoon. Combining it with the jutting shoulder wheels, bucket like head sculpt, and oddly shaped missiles is just too much. If they made another version with the standard arms, head, and missiles That would be perfect to me.

An additional license could have added more decals and specific tires but this line is paying more for lawyers than plastic as it is.

 

Tracks  

 

Personally I absolutely hate MP21 Bumblebee,his color is just too Movie-ish,but on the flip side I can't get over how drop dead gorgeous MP21G is,it is like a hybrid Bumblebee/Goldbug look to him.I just wish Takara had done MP21G by itself and forgot about doing MP21.

I may be the only one who thinks that but what can I say its just my opinion.

 

I've been pretty selective in my Masterpiece buying and, so far, not too shabby.

Hasbro editions of MP-01 - a fantastic if awkwardly weighted figure

MP-03 - nice but the wrong color and feels like a model kit

TRU 2nd run Grimlock - kind of floppy during transformation but solid in both modes

Hasbro edition MP-10 and YOTH - fantastic! No complaints!

Star Saber - fantastic and no complaints!

G2 Sideswipe - also fantastic and no complaints!

Hasbro edition Soundwave - fantastic and no complaints!

Hasbro edition Prowl - fantastic and no complaints!

Hasbro edition Bluestreak - mine has some issues with one of the lower legs that makes it somewhat difficult to transform and peg everything together in vehicle mode...but it can be done.

MP-21G - decent figure. No real issues, per se...just a tad underwhelming for the price of $40.

 

What is this "skay-ull" thing you speak of? 

 

I have Wal-scream, Takara Skywarp (both the old seeker mold) and US Thundercracker (the new mold), and while I'm fine with both I can't get all the hate the original seeker mold gets. Yes, it has hip kibble, and the legs aren't exactly cartoon accurate in bot mode - but it makes for a WAY better alt mode than the newer mold. The newer mold makes some concessions towards the bot mode's legs that make it look like the jet is carrying steel girders underneath it whereas the old one is sleek and looks more like a real jet. Also I don't like the swingarms that hold the null rays on; the partsforming guns/missiles on the old mold makes for a better looking altmode. The original seeker mold is a rare example of a Transformer with a jet/plane altmode that looks good from any angle, as most TF jet toys go for "jet on top, stacks of shipping crates on the underside". I'm looking at you, Combiner Wars Cyclonus.

As far as MPs that I genuinely dislike... I can't say I own any, just a few that are okay but not terrible. MP-5 is a pain in the ass to transform but he's not so bad on display so I can give that a bit of a pass. 20th Anniversary OP has some paint chipping issues and mine has a busted knee ratchet that I repaired years ago... and the truck mode is pretty bad compared to MP-10... but the bot still looks pretty boss. I did, however, replace the short stacks with custom parts because that DID look awful. It was amazing 11 years ago though.

I don't own Star Saber mainly because I couldn't care less about the character, so I can't make a call on that one. Tracks looked a little questionable to me engineering-wise and I never really cared for Tracks anyway, so I passed on that one. I'm just hoping that Ratchet won't be a crapbucket because I've been waiting 30 years for someone to FINALLY make a Ratchet that wasn't a piece of ugly junk. I have it on order but from what I've seen of it it could go either way.

 

MP-01.

Fun gimmicks, looks lovely standing there, but that's about it.

His arm proportions are weird, he can't hold his gun, his alt-mode is laughable, he's so pointlessly heavy his legs can't bend without doubling over... at least MP-03 has a wonderfully delicious alt-mode. But Prime? He's just a giant waste of space.

 

MP-09 but only because he must start fights with the other bots in the room when I leave. I keep coming back and his arms are laying on the ground. Clearly they were ripped off at the sockets by Galvatron.

 

Megatron for reasons everyone has pointed out already, and Bumblebee, purely because his arm panels do not cover up the gaps in his arms where the hands are stored. why the heck give him arm panels then, actually, why the heck does he have gaps in his arms anyways? I would expect that from a general figure's release, not from the MP line.

 

My least favorite is and always has been MP01. Solely because his alt mode is such a terrible mess that kind of resembles a semi but not really. Man, I am sooooo happy Mp10 is thing.

And while he's not my favorite I'll white knight for Megatron. He's definitely too skinny but I love transforming him and his alt mode is lovely looking.

 

Thundercracker - He is large and a piece of hefty plastic that reminds me of the days of ROTF when you had panels everywhere just to make it complicated and I hated the days of complication and love the days of easier transformations.

I would add Prowl here too but he is at least SOMEWHAT better and he is the only other Masterpiece I have. It is because of these two that I refuse to touch another Masterpiece in my life.

 

Of the ones I have owned, I am forced to give the standard answer of MP-05. Just traded that POS at TFCon last month for TFs I needed a lot more.

So of the ones I still own, I have to say Wal-Mart Skywarp. I hate those tail fins hanging from his waist. The redesign is much better.
Oh, and for the record, I adore my MP-01  

 

This is funny because the MP Datsuns are my favorite mold following closely by the MP seekers.