(By which I mean how many perk points are used in the tree.)
My vote is Speech. Like there is any shortage of expensive and sellable things in the game - there's no point in making things more valuable, because it just means more fast-traveling around to get (fairly useless) gold from vendors. Yeah, I know one can invest in the stores, but, it's easy to have 20 grand by level 10 with minimal effort.

Lockpicking is a close second, as one can pick a master lock with extremely low lockpicking, and lockpicks are everywhere.

Agreed, but i voted Lockpick.

I totally agree, I have like 180k on my character now, without putting any points in speech, and tbh, I dont really need to sell stuff any more, I have all the houses, and more than enough to pay for the things I need.

Lockpicking at leaat has the perk to increase the chance of finding special items. That's something money can't buy.

Lockpicking.

I'm still struggling for cash in most of my games.

As long as you have a ton of lockpicks. Maybe its me, but finding the right spot for Master locks is a pain in the ass

I have a three way tie. Even on my thief/assassin character, who's lvl35, I have yet to put anything into pickpocketing, lockpicking or speech.

I voted speech. I can't imagine ever putting points into speechcraft, especially for a min/max character where you're keeping close tabs on your limited perk points.

My least used skill however is pickpocket. If it weren't for the Thieves Guild quests, I'd have no reason to do it. I'm hoping mods make Speechcraft, Pickpocket, and Lockpicking more significant.

Why the heck is block there ? It's one of the biggest if not the biggest feature of my main character archetype and the same goes for many of my more melee-centric friends who play sword'n'board.

Anyway my vote falls somewhere between speech and lockpicking. Both have interesting extra perks but the very core features of both perk trees are very much so useless and could easily be skipped.

I would believe that either speec or lockpicking is the least perked skill tree. I would guess they are used a lot though since they are in a practical sense passive(as in you end up using them no matter what you do, more or less).

How dare you include block.

I have no idea why Block, Heavy Armor, and Light Armor are on that list.

I voted Lockpicking, but Speech would be my second choice. Every single perk in both trees is easily skippable. At least some of the Speech perks are convenient. Lockpicking is just totally a worthless tree though. Pickpocketing has the epic Extra Pockets, and while Poisoned, Misdirection, and Perfect Touch aren't actually useful, they are fun novelty perks.

Why is pickpocket even in this list?. The perks arent great but you can use it to train for free and thus raise a few levels. The skill itself raises extremely fast, you can raise it to 60 in a hour or so. The perk that raises inventory space is very useful too, especially when you consider that the heavy armor perk to make armor weightless is bugged. Another useful feature of pickpocketing is that you can use it to obtain enchanted amulets early on, as these things only start appearing as loot at later levels and usually in chests defended by powewrful bosses. And of course, you can become rich by stealing things. The only problem i find with pickpocket is that since it raises so easily you never need to spend a single perk in it, but the skill itself is very useful.

dont forget the ability to get a whole city of naked people once you max it

Definitely Lockpicking. It's the least desirable perk tree in the game, because:

• With practice, you can pick anything up to Master locks without perks, breaking only a few lockpicks in the process.
  
• Quick Hands perk (pick locks without being noticed): Only useful in a very few places (even fewer with good Sneak).
  
• Wax Key perk (make wax key for any lock you pick): Interesting idea, but almost entirely useless.
  
• Golden Touch perk (find more gold in chests): There isn't nearly enough gold in chests to begin with for this increase to be worthwhile.
  
• Treasure Hunter (50% higher chance to find special treasure): Too bad crafted gear is always better (i.e., perk a crafting skill instead of Lockpicking).
  
• Locksmith/Unbreakable: Easily skippable convenience perks, there are tons of lockpicks for sale.

who the hell least uses heavy/light armor even less then lockpicking and speech?

Armor and blocking seem pretty important in my opinion. I voted pickpocketing

I vote lockpicking.

If you level up lockpicking through normal playthrough, I don't even see why you would feel the need to have unbreakable lockpick when there are no locks to be unlocked.

Pickpocketing for me, I just don't get around to picking many pockets. Impossible to avoid using speech and lockpicking in normal play.

The lockpicking skill tree (for perks) would've been allot more useful if the Oblivion system was still used. The two key items for bypassing it where neutralized in Skyrim. One is not even in the game and the other needs to be given up to finish a quest line.

For me personally, I have only used pickpocketing twice. Maybe I'll try more of it later but it isn't a need, even for my thief character.

For me personally it would be Lockpicking. I haven't even looked at the tree. I have a knack for it or it's just extremely easy. My Lockpicking was about 25 and I went to the Thieves Guild and saw that there were some chests for lockpicking. I did them all and when I got to the Master lock I managed to do it in 3 picks. I broke 2 of them and the third one I managed to figure how to open it. It was fustrating because the first one broke instantly. The second one I managed to move a little and it rattled so I took an estimate and moved the lock towards the left and I got it right to the near end and it snapped. I had to find my place and move it a split then I managed to open it. I'm pretty sure after a while there is a feeling to it. If it moves so much and then stops I can guess where abouts I should move and it goes futher. The hard the lock the less distance you need from your previous place. Well that's my opinion. I bet I'm just lucky

Lockpicking of course. Is there even anyone who perked this?

Block and armor skills don't belong on that list.

Pickpocket I like the +100 carry weight, but I'm a packrat and hardly need all my skill points to have a good character build.

Speech I like to invest in merchants because I can't stand leaving expensive items in dungeons and I like to be able to sell them easier, and again I don't really need all my skill points (I don't invest in speech until post-50 but I'm already level 59). Yes, I'm already filthy rich like most people but I'm OCD about my loot, don't care about money though.

Lockpicking.... Well I get master locks with 2-4 picks and most other chests with 1 or 2 picks. So I never saw any reason to even consider putting perks in to it. So yeah, lockpicking is the most useless (speech is a close second though).