Holmes Schoey Lyons Maggsy Sinfield Harris Burrow Coleman Dick all deserve a mention in no particular order.

I would say Iestyn's best position was at 1 for Leeds.

Its a weird one because a lot of Leeds' best halves were arguably better in other positions, Schoey- centre, Kev- 13

I am a believer that you have to look at performances in big games, not just against the minnows, for that reason (counting Kev as 13) it has to be John Holmes, with Mags and Burrow as notable mentions

Schofield, closely followed by Harris.

McGuire, Burrow and Sinfield all had good attributes but none was really the complete half-back. McGuire came close in 2010 before his injury, but even then his electric pace had gone.

I didn't see Lyons, but I still have a bit of soft spot for Goulding during his brief time with us. Also Tony Kemp seemed to be a classy player who didn't really come at the best time at the club - the Bell years. Seem to recall he wasn't afraid to give it a bit of niggle with the big Bulls team of 1996+, which was amusing.

Lewis Jones for me. He had the lot in his prime and made it look so easy when he rally decided to turn it on. Also total poetry in motio.
Schoy and John Holmes tie as close seconds, both reading the game well. Holmes could put people in space with exquisitely timed passes an Schoenberg had that ability to make things happen out of nothing in an explosive manner when you could not anticipate it.

How did Gary Schofield become a modernist composer? Blooming predictive text.

Schofield when married with Goulding in 1991/92 was the very best half back partnership Leeds have had in my time watching them - Schofield was at his very best then even though the season as a whole ended up becoming a bit of a disaster.

It's disheartening to wonder what might have happened had Goulding not left. Schofield was never quite as consistently effective again for Leeds after that; it was right in the middle of an embarrassing sequence where we had a new scrum half at the start of every season and Bobby (as he was then) was the only one which really worked out.

Lewis jones was before my time, john Holmes for mine. Schofield was a great talent and a wonderful try scorer but I'd take Holmes and sinfield. They dragged teams over the line in big games and Holmes did a ton of tackling for years on end. Sinfield's cover tackle on eastmond won the 2011 GF and he produced that type of effort over and over again.
Schofield provided a lot of magic moments and you could argue he did not have some of the tough nuts supporting him that Holmes and sinfield did but they could really tough it out. Harris, McGuire and cliff Lyons were all top draw.

This!

good assesment. Lewis Jones and John Holmes were before my time but i know they are Leeds greats. I picked Schofield because nothing seemed impossible with him and he was great to watch live.

Sinfield, kicking aside without being great, was solid in every area, and was udoubtably the reason we won 2-3 more GFs than we perhaps should have in his era. one of the best game managers around and will only truly be fully appreciated in years to come and as time goes on. a fine wine as you will

Schofield or Lilley.

Alan Hardisty was a pretty special player too - although he was well passed his best when he came to Leeds

Probably been around more than most that are posting but in my opinion
1 Lewis Jones
2 Mick Shoebottom/ John Holmes
4 Kevin Sinfield

Lewis Jones was the maestro with so much talent and the best SO in my opinion. That is not to underestimate the superb skills of Holmes and Schofield who were also a delight to watch. Jones and Holmes both had great heads-up awareness with the ability to put others into space and they were also top place kickers. Both Jones and Schofield had the ability to ghost past defenders with ease and bring the crowds to their feet with individul brilliance. For all action consistency, toughness and instinctive play Mick Shoebottom would make my list too.

All three were game changers so the batting order for me is 1. Jones 2. Holmes and 3. Schofield 4. Shoebottom

In my 30+ years as a fan it's Schofield by a country mile for me.... As others have said, as a half, he had everything. A real threat ball in hand, vision, creativity, long and short kicking game, pace and strength and alright defensively - unfortunately for the majority of his time with Leeds, he didn't have the supporting acts around him to make us successful.
Unfortunately, the way juniors are coached and the way the game is played, I doubt we'll see a half with such a complete game come through in the British game.
Harris at his peak was exceptional (god knows how many Tissot watches he must have for his MOM awards on sky), but I don't feel he had it all like Schofield did. Harris would have been found out eventually, he was brilliant at what he did, but he wasn't as unpredicatable as Schoey - Schoey would just turn it on regardless of field position or what was happening in the game and make a break, chip over and regather etc.... unplayable.
McGuire has been amazing in the current set up, and has been the perfect half to play alongside Sinfield and Burrow, but he's not got the all round game Schofield had.
If you could drop any player into today's environment, with the right attitude (something Schoey didn't always have) and today's training, sports science etc, Schofield would be the better than Thurston IMO.

Not much to add to the comments above with which I generally agree except to say that I always had a soft spot for Creasser who was plagued by shoulder injuries throughout his career. It was his premature departure that forced Ward into trying Schoey at no 6 when all else had failed. It always grieved me that Sean Edwards won so many trophies whereas his infinite superior Schofield won hardly anything.