http://opentracker.bt.i2p/a
http://opentracker.dg2.i2p/a
http://opentracker.eeptorrent.i2p/a
http://opentracker.fattydove.i2p/a
http://opentracker.r4sas.i2p/a
http://opentracker.simp.i2p/a
http://w7tpbzncbcocrqtwwm3nezhnnsw4ozadvi2hmvzdhrqzfxfum7wa.b32.i2p/a

Working I2P non-open trackers, meaning they only track torrents published at their own website.

http://tracker2.postman.i2p/announce.php

Currently Down I2P Trackers:

http://ahsplxkbhemefwvvml7qovzl5a2b5xo5i7lyai7ntdunvcyfdtna.b32.i2p/announce.php
http://atia42hvtnklmilskllirvl5e27letgqghyuvrlvtaktyg32kqwq.i2p/announce
http://crs2nugpvoqygnpabqbopwyjqettwszth6ubr2fh7whstlos3a6q.b32.i2p
http://lnQ6yoBTxQuQU8EQ1FlF395ITIQF-HGJxUeFvzETLFnoczNjQvKDbtSB7aHhn853zjVXrJBgwlB9sO57KakBDaJ50lUZgVPhjlI19TgJ-CxyHhHSCeKx5JzURdEW-ucdONMynr-b2zwhsx8VQCJwCEkARvt21YkOyQDaB9IdV8aTAmP~PUJQxRwceaTMn96FcVenwdXqleE16fI8CVFOV18jbJKrhTOYpTtcZKV4l1wNYBDwKgwPx5c0kcrRzFyw5~bjuAKO~GJ5dR7BQsL7AwBoQUS4k1lwoYrG1kOIBeDD3XF8BWb6K3GOOoyjc1umYKpur3G~FxBuqtHAsDRICkEbKUqJ9mPYQlTSujhNxiRIW-oLwMtvayCFci99oX8MvazPS7~97x0Gsm-onEK1Td9nBdmq30OqDxpRtXBimbzkLbR1IKObbg9HvrKs3L-kSyGwTUmHG9rSQSoZEvFMA-S0EXO~o4g21q1oikmxPMhkeVwQ22VHB0-LZJfmLr4SAAAA.i2p/announce.php
http://omitracker.i2p/announce.php
http://opendiftracker.i2p/a
http://opentracker-actix.i2p/a
http://opentracker.skank.i2p/a
http://psi.i2p
http://tracker.crypthost.i2p
http://tracker.killyourtv.i2p
http://tracker.thebland.i2p
http://tracker.welterde.i2p
http://tu5skej67ftbxjghnx3r2txp6fqz6ulkolkejc77be2er5v5zrfq.b32.i2p/announce.php
http://uajd4nctepxpac4c4bdyrdw7qvja2a5u3x25otfhkptcjgd53ioq.b32.i2p

Unsure if all the ones currently down are just down temporarily. Some I suspect will come back (e.g. skank.i2p has been around forever so I'd be surprised if they're permanently gone).

EDIT: Browse notbob, especially their tracker listing for hints on current I2P torrent trackers and sites http://notbob.i2p/cgi-bin/defcon.cgi?category=tracker