Technically Abjurant Champion can be reworked as a psionic class, but there are no actual rules on it, and clearly parts of the class would need to be reworded. 5 levels = +5 ML
Anarchic Initiate is 10 levels of 10 ML of stuff that seems to randomly screw you or other people, but no real net benefit, unless you think being able to plane shift people to limbo at 10th level is cool. Or, if you think sending the party treasure away is cool.
Elocator is only good the first level, and it requires spring attack, which is two dead feats (dodge and mobility) That's a hefty feat tax to be able to float 1 foot off the ground forever.
Now Mindbender has a dead level at 2nd, but the first level is nice Eternal Telepathy. problem is all four skills you have to buy are Cross Class, so you need to buy a level of Anarchic Inititate to get the skills first. The psionic version only needs 3rd level powers manifested, so you can pick it up at 6th for the Erudite.
Shadowmind has a dead level at 2 and the first lever power just ain't worth the effort.
The Arch Psion is worth it, even with the steep 3 feet tax. Unlimited Shape Power and Greater Psionic Focus +2 and +3 (which stack) are my top 3 picks. I'd actually only take 3 levels, normally. But the Reach Power bought twice does have its appeal.
Now Shadow Mind (not be be confused with Shdowmind) is rather easy to get into, and has some nice perks for the first 4 levels. It stacks with your psicrystal (other PrCs do not), gives you access to new Astral Construct menu items, gives you some limited DC bonuses, and at 4th you get a funky shield of shadow and telekinetic power forged from the fears of your own subconscious that grants a +7 AC and 30% miss chance chance based on concealment. When does that ever get old? You almost don't mind the 1 Feat tax. Alas, it doesn't get cool again until 8th (where you get power resistance) and 10th where you get to copy yourself and use your duplicate to manifest powers through. Could be awesome, but a bit of a slog to get to.
Crystalsinger is only for people who want to make items.
Finally, The percipient is just plain weird. Unless the idea of a third eye in your forehead that shoots gaze attacks (kinda meh attacks at that), and grants a heafty Initiate PENALTY is your think, I don't know if I'd even look at it.
Those are all the classes that don't cost you manifester levels Of all the other psionic PrCs, is there any that MIGHT be worth the loss of Manifester level?