Your intuition is leading you astray.  Siege is no better for attacking towns than any other.  All the troop types are equal.

About the only consideration when choosing is for clanmates to choose different specialities.  The clan will (after a very long time) benefit from having a spread of troop types.

Generally John has good insight on the game mechanics, so would largely agree with his analysis.

However, if everyone cared to respond I am sure you would get many a different point of view on 'what is the best'

Besides this, the game is not as straight foward as it seems, and is not always as equal as it appears either,according to posts on the forum, many of which I haven't investigated myself.

You may wish to check  and confirm what connected hero and shaman gear is available and which is not. 

First obsevation is,doesn't matter what you have if the town is shielded, and if it isn't,what is best may vary according to yours and the opponents standings even if you have the same troop type.

Second observation, look at the troop's statistics and consider their relative merits, and for other than for fighting ,if you are going to do any resource acquisition.

They are all pretty much the same, i agree with john, however ill add, siege carrys more than calvary but calvary is faster. So if yielding is your forte then pick one with higher capacity. Tbh tho in late game it doesnt matter really besides your clan coordination, i just picked the one that looked the coolest to me 

You have fallen into the trap I first encountered on you tube  when I started playing the game.

It is still perpetuated there, and now here,by you.

It  is caValry,  not caLvary.

caValry = horseback troop. 

caLvary = religous context, enduring tribulation.

While I am about it.

It's   K Czar  not  Kaz er

     Celt is  Kelt  not  Selt.

To specify I want a troop type meant for attacking and defending. I really wanna be able to go to asgard and jotunheim with a good set of fighter troops.

Can't help you specifically with those places, but would refer you back to the other answers  to your question,which suggest that there is no real choice to be made, however I would restate my advice and consider which Shaman  is better represented  for use there.

Creating a strong army takes rather a lot of time.  Your troops can be improved in numerous ways and the improvement comes about in small increments.

You need a well developed hero and shaman - the shaman being the one apropriate to the troop type you choose.  The hero needs a set of legendary gear (the set apropriate to the troop type) and then you must improve each of those as far as you can.  The same for the shaman.  You must craft legendary gems and runes and then work to improve those as far as you can.  You must max out knowledge and then advance secret knowledge as far as you can.  Of a slightly lesser importance, your palace needs to be at level 40 and all your buildings also.  Your chosen troop type must be upgraded to the maximum in Valkyries Citadel.  You must acquire a number of town skins and advance them as far as you can.  Maxed Aesir help a bit.

If you do these things by playing Vikings:War of Clans it will take you six or seven years, playing daily.  If you come to the site to shop how long it takes depends on how much you spend.

To be effective in Jot or Asgard you also need half a dozen or more clanmates equally advanced.

The choice of troop type you make has no effect whatsoever on any of this.

The above is so correct.

FB blogs suggest melee is the best value for money - ie cheapest to replace, relatively fast and reasonable carrying capacity but the real secret is to concentrate on maximising the knowledge of just one or two types to start with.

As the others have suggested the different troop types doesn't seem to make much difference. The tables suggest a 25 or 50% advantage but in my experience in real terms it is nearer 10% ( ie instead of killing 10 of a weaker type your troops kill 11). Outnumber your opponent troops by1000 troops to 1 and your troops will kill way more than an extra10 % . 

Grow up 😂😂

Hark at the kettle.