Is Gundam GOOD?

it's very hit-or-miss

I haven't seen a lot of Gundam compared to others, but I think there's definitely some that are worth seeing but I can see why others don't work for people. If I'm being real honest with myself my favorite Gundam anime I've seen are ones Tomino did not work on and while I liked the original MSG and Zeta I have issues with them (ZZ is imo trash though I liked Judau). I can see why its a hit and miss franchise and I think whether someone would bond with it or not depends on their taste. I encourage trying it all the same.

The thing that I love about Gundam is that is conceptualy a war story (mainly) and is usually told in a layered way (as in you get to see the perspective of various sides of the conflict).
Serious gundam heads would tell you that you should start with 0079 (the first series basically) but since that's a bit long, maybe start with the Origin OVA's, I think those are great, and a great presentation of the characters.
Iron Blooded Orphans is really good as well, and since it belongs on a separate universe you don't really need to watch everything to understand it.

Tomino fan here, I love the Gundam series even though it is an incredibly hit-or-miss franchise. Sunrise can release the best anime of it's decade and next year they can release the worst of the worst.

I recommend starting with the 0079 (og gundam) compilation movies. They get rid of the super robot elements of the first show, fix animation issues of the first third and they introduce some key concepts earlier. After that you can watch whatever you want since most shows borrow elements from 0079, though I recommend following the production order for the original UC saga (Zeta->ZZ->Char's Counterattack)

Gundam Seed is one of the best recieved ones in the series. Thats the one i recomened

Gundam Good. You can technically start pretty much anywhere as long as you aren't doing something crazy like watching ZZ gundam before any of the earlier Universal Century series, but if you wanna see Gundam in it's most primordial state first and foremost definitely start with the original anime series for 0079, it's pretty lit. Haven't seen the compilation movies yet so I can't really vouch for them like KrissJoe is but I've heard from my own homies that the movies introduce their own problems so it's probably best to start with the anime series instead if you want a more pure initial watching experience. I found that it starts a little slow in my opinion, but when it starts going it really gets going, probably my fav Gundam of the series I've watched despite some of what people might consider to be flaws.

Yes, Gundam is very good (speaking of the franchise).

However, old series and movies have a different pace from more recent shows that can bother newcomers.

That's why despite I definitely agree that UC is the best universe, I think alternative timelines (Gundam Seed, Gundam 00 and Gundam IBO) are best options to start with.
Kidou Senshi Gundam Seed
Kidou Senshi Gundam 00
Kidou Senshi Gundam Tekketsu no Orphans

Then if you like one of them, you should consider watching the original show or its compilation movies before going further in UC, the original universe.

Gundam just comes down to your personal taste, if you like military pieces that depict war in the future with some pretty cool supernatural ideas here and there then you may like it. It's inevitably going to either have its detractors or non-fans cause a lot of people don't like that or how it's done, especially because it's a massive franchise there are plenty of people who reflexively dislike it for that reason alone.

Average ratings are a dumb system to rely on anyway, they're only accurate so often and most of the higher rated shows are just new anime that everyone obsesses over. If a show that's over 20-30 years old manages to hold a rating of at least 70% that's already impressive in its own right.

If you want to watch a Gundam anime just pick any, it's technically better to start with the original 1979 anime but it's not really necessary. And most importantly don't rely on ratings all the time, that's going to ruin your perception and enjoyment of many good shows that don't get worshipped by a hivemind. For instance even though Iron Blooded Orphans is rated very highly for a Gundam anime I've seen more hate for it than love in the community and the reverse goes for ZZ Gundam which is one of the lowest rated in the series.

If you really want to try Gundam just pick one and see what you think. This is some of the higher rated ones if you must pick a show with a better reputation

Mobile Suit Gundam
Mobile Suit Gundam 0080 War in the Pocket
Turn A Gundam
Mobile Suit Gundam 00
Mobile Suit Gundam The Origin
Mobile Suit GUNDAM Iron Blooded Orphans

It's probably going to depend on series but arguably since there's so many different Gundam series, there's a very good chance there's at least one that will appeal to you.

Tomino at his peak is untouchable

What it for yourself. This is a bad question.

As someone with vastly varying tastes in media I do think so.
The issue with Gundam as a franchise is that it's inconsistent with quality, and bandai has clear favoritism for certain parts of the franchise making arguably better series have to be cut short, or not be continued in any meaningful way.
Because of this you get shows that are like 9-10/10 and stuff that ranges from like 3/10 to 8/10.
However there are certain things that I would say are an absolute must try:
Turn A Gundam
MSG compilation films
Zeta Gundam
Double Zeta Gundam (If you like goofier stuff)
The Witch From Mercury
and if you don't really care about inconsistent writing
Iron Blooded Orphans

However, for the love of all that is good and holy, don't watch Seed

Yes.

I dunno.