What do you regard as noteworthy differences in the popular pali to english translations?

To begin, any Sujato translation related to Four Noble Truths & Dependent Origination is best ignored where "ponobbhavikā" is wrongly translated as "future rebirth"; "punabbhavo" as "future lives"; "jati" as "rebirth" and "abhinibbatti" as "reincarnation".

Starting with Dhammapada:

1. Dhp 1 has Thanissaro engaged in solipsism by translating "dhamma" as "things" or "phenomena". Buddharakkhita's is the reasonable translation of "dhamma" as "mental states"; although I would translate "dhammas" here as "modes of conduct".

2. Dhp 203; probably all translators have translated "saṅkhāra" wrong. I would translate it as "mental fabrications".

3. Dhp 278 is correctly translated by Buddharakkhita; where dukkha is translated as "unsatisfactory" for the characteristic and "suffering" for the mental state.

Moving to the Majjhima Nikaya:

1. MN 1; Thanissaro is close to solipsism; translating "conceives earth" rather than "conceives self in earth".

2. MN 9; probably due to Nanamoli, correctly does not translate sankhara as "volitional" formations and correctly translates namarupa as "mentality-materiality"; which Bodhi does not do in his SN.

3. MN 38; Thanissaro and Sujato misguidingly translate sambhavoti in in a way that refers to the arising of the functioning of consciousness rather than the origination of consciousness into suffering.

4. MN 38; Bodhi, probably due to Nanamoli, correctly does not translate sankhara as "volitional" formations; which Bodhi wrongly does in his SN.

5. MN 62; Thanissaro translates "makes the earth property fade from the mind", which sounds wrong, since DN 11 says the four elements cannot cease without remainder.

6. MN 118; all translators translate sabbakaya, kayasankhara and cittasankhara wrongly. Sabbakaya, per the Paṭisambhidāmagga & MN 118, means "all bodies", referring to the breath-kaya, rupa-kaya and nama-kaya. Kaya and cittasankhara means "body & mind conditioner", although this is not literally correct, which is literally "condition for the body & mind".

7. MN 135; all have worldly translations of upapajjati, āgacchati & paccājāyati; which an examination of the suttas (examples AN 4.197 & AN 7.64) shows can mean differently than mere "rebirth".

8. MN 148; Thanissaro uses "obsessions" for "underlying tendencies"; which while not fatal; is exaggerated. There is a big difference between an underlying tendency and an obsession.

In the Samyutta Nikaya:

1. SN 12.19; all translate "kaya" to infer "physical body", where Bodhi used to bracket "conscious body". This appears wrong. "Kaya" here appears to refer to the "grouping" or "collection" of the five aggregates. Also 'external namarupa' here refers to "external minds & bodies" rather than the nonsensical "external name-form".

2. SN 12.25 and everywhere else in this kamma context (such as AN 3.61) wrong translate "sukhadukkhaṃ" as "pleasure & pain", which implies "vedana"; rather than "happiness & suffering", which implies the end result of kamma.

3. SN 13.1; all translators falsely translate "sattakkhattuṃparamatā" as "seven more lives at most remaining"; where the Pali only says: "seven times at most".

4. SN 22.59; similar to Buddharakkhita above, N.K.G. Mendis has translated "dukkham" accurately as "unsatisfactory'.

5. SN 22.79; Bhikkhu Bodhi most appropriately translates "pubbenivāsaṃ" as "past abodes" rather than "past lives" because SN 22.79 is most obviously not about "past lives".

6. SN 23.2; Bhikkhu Sujato most ridiculously translates "satto" as "a sentient being" because "satto" only means "a being" and because "sentient being" is completely contrary to the intent of the text, being the same as the view of Mara in SN 5.10.

7. SN 38.14; Bhikkhu Bodhi has the proper translation of "suffering due to pain... formations... change (vipariṇāma)". The others are wrong. SN 22.1 makes it clear "vipariṇāma" ("change") only leads to suffering when there is attachment; just as MN 44 makes it clear the "vipariṇāma" of feelings is painful when they are underlied by underlying tendencies.

In the AN:

1. AN 10.58; generally all internet translations are wrong; however this was correctly explained here by Piotr & Deele.

General issues:

samparāyikā is translated by all three majors as "lives to come" however samparāyikā is found in Iti 44 and appears to not mean "lives to come" but, instead, merely "the future", as follows:

These two Nibbāna-elements were made known By the Seeing One, stable and unattached: One is the element seen here and now with residue, but with the cord of being destroyed; The other, having no residue for the future (samparāyikā),

namarupa madly translated now by all three majors as the Brahministic "name-form"

From Dhp 282 translated by Ven. Buddharakkhita:

Wisdom springs from meditation; without meditation wisdom wanes. Having known these two paths of progress and decline, let a man so conduct himself that his wisdom may increase.

The same was translated by Ven. Thanissaro here:

From striving comes wisdom;
from not, wisdom's end.
Knowing these two courses
— to development,
decline —
conduct yourself
so that wisdom will grow.

The word "meditation" in one translation is the same as "striving" in the other. The Pali word here is "yoga" as seen here, which also translates it as "meditation".

Ven. Thanissaro's translation of Dhp 277-278 translated "sankhara" as "fabrications" and "dukkha" as "stress".

When you see with discernment,
'All fabrications are inconstant' —
you grow disenchanted with stress.
This is the path
to purity.

When you see with discernment,
'All fabrications are stressful' —
you grow disenchanted with stress.
This is the path
to purity.

Ven. Buddharakkhita's translation of Dhp 277-278 translated "sankhara" as "conditioned things" and "dukkha" as "unsatisfactory". I feel this is more accurate.

277. "All conditioned things are impermanent" — when one sees this with wisdom, one turns away from suffering. This is the path to purification.

278. "All conditioned things are unsatisfactory" — when one sees this with wisdom, one turns away from suffering. This is the path to purification.

In MN 49, there was a "consciousness without surface" or "consciousness that is invisible, infinite, radiant all round" (viññāṇaṃ anidassanaṃ) that some people imagined to be a permanent consciousness of sorts, which turned out to be a mistranslation, according to the answers of this question. The sutta was talking about Nibbana. I've also explained this in detail in this answer.

Ven. Sujato translated part of MN 49 as:

Consciousness that is invisible, infinite, radiant all round—that’s what is not within the scope of experience based on earth, water, fire, air, creatures, gods, the Creator, Brahmā, the gods of streaming radiance, the gods replete with glory, the gods of abundant fruit, the Overlord, and the all.
Viññāṇaṃ anidassanaṃ anantaṃ sabbato pabhaṃ, ...

It should rather be:

That which could be known or cognizable (i.e. Nibbana), is invisible, infinite, radiant all round—that’s what is not within the scope of experience based on earth, water, fire, air, creatures, gods, the Creator, Brahmā, the gods of streaming radiance, the gods replete with glory, the gods of abundant fruit, the Overlord, and the all.
Viññāṇaṃ anidassanaṃ anantaṃ sabbato pabhaṃ, ...

Ven. Sujato translated "jāti" in SN 56.11 as "rebirth".

Now this is the noble truth of suffering. Rebirth is suffering; old age is suffering; illness is suffering; death is suffering; association with the disliked is suffering; separation from the liked is suffering; not getting what you wish for is suffering. In brief, the five grasping aggregates are suffering.

In SN 56.11, Ven. Bodhi translated "jāti" as "birth". This is quoted below. Ven. Thanissaro also translated it here as "birth".

“Now this, bhikkhus, is the noble truth of suffering: birth is suffering, aging is suffering, illness is suffering, death is suffering; union with what is displeasing is suffering; separation from what is pleasing is suffering; not to get what one wants is suffering; in brief, the five aggregates subject to clinging are suffering.