This could be in the wrong forum, sorry, I don't know where to post it in that case.
I am looking for legit online casinos that not only deposit and withdraw from bitcoin (Winning poker network), but you actually PLAY and maintain your balance in bitcoin/altcoins. I am looking for texas holdem poker with real people. Does anything like this exist?
I know of betcoin.ag but they have very bad reputation.
Also, SWC has almost no traffic.
I know about nitrogen sports (seems like the best option), but they have very few games and I don't like the software.
I've heard of virtue poker coming up. Hopefully something like that works out.
In addition to the poker sites you listed above, there is also:
https://btckings.com/166676 (remove the numbers at the end if you don't want to go through my referral link). It's a new site, not much traffic yet especially at non-peak hours, but they are actively working on it. Currently they have in-house bots at some of the micro tables which is the site's way of generating action at the moment. the bots are very, very soft and easily exploitable (aka free bitcoins, basically).
btckings.com has a thread here on the forums you can read here:
https://bitcointalk.org/index.php?topic=2008313.0 (not a referral link). THe rep will help you if you have any questions and/or problems regging to the site.
Just to add, I know you already mentioned betcoin.ag, but poker players there have access to the Winning Poker Network tournaments, if in case you didn't already know. Also, poker tracking software works on betcoin.ag. I use HEM2, and I'm not sure, but I think PT3 and PT4 works also. Good Luck.
*Edit: Forgot to add, betcoin.ag also accepts litecoin and etherium, since you inquired about places that accept altcoins